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   *  AndroidIDE is free software: you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation, either version 3 of the License, or
   *  (at your option) any later version.
   *
   *  AndroidIDE is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *   along with AndroidIDE.  If not, see <https://www.gnu.org/licenses/>.
   */
  
  /*
   * Copyright (c) 2004, 2006, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package jaxp.sun.org.apache.xerces.internal.jaxp.datatype;
  
  import java.io.Serializable;
  import java.math.BigDecimal;
  import java.math.BigInteger;
  import java.util.TimeZone;
  import java.util.Calendar;
  import java.util.GregorianCalendar;
  import java.util.Date;
  import java.util.Locale;
  
  import jaxp.xml.datatype.DatatypeConstants;
  import jaxp.xml.datatype.Duration;
  import jaxp.xml.datatype.XMLGregorianCalendar;
  import jaxp.xml.namespace.QName;
  import jaxp.sun.org.apache.xerces.internal.util.DatatypeMessageFormatter;
  import jaxp.sun.org.apache.xerces.internal.utils.SecuritySupport;
  
  /**
   * <p>Representation for W3C XML Schema 1.0 date/time datatypes.
   * Specifically, these date/time datatypes are
   * {@link DatatypeConstants#DATETIME dateTime},
   * {@link DatatypeConstants#TIME time},
   * {@link DatatypeConstants#DATE date},
   * {@link DatatypeConstants#GYEARMONTH gYearMonth},
   * {@link DatatypeConstants#GMONTHDAY gMonthDay},
   * {@link DatatypeConstants#GYEAR gYear},
   * {@link DatatypeConstants#GMONTH gMonth} and
   * {@link DatatypeConstants#GDAY gDay}
   * defined in the XML Namespace
   * <code>"http://www.w3.org/2001/XMLSchema"</code>.
   * These datatypes are normatively defined in
   * <a href="http://www.w3.org/TR/xmlschema-2/#dateTime">W3C XML Schema 1.0 Part 2, Section 3.2.7-14</a>.</p>
   *
   * <p>The table below defines the mapping between XML Schema 1.0
   * date/time datatype fields and this class' fields. It also summarizes
   * the value constraints for the date and time fields defined in
   * <a href="http://www.w3.org/TR/xmlschema-2/#isoformats">W3C XML Schema 1.0 Part 2, Appendix D,
   * <i>ISO 8601 Date and Time Formats</i></a>.</p>
   *
   * <a name="datetimefieldsmapping"/>
   * <table border="2" rules="all" cellpadding="2">
   *   <thead>
   *     <tr>
   *       <th align="center" colspan="3">
   *         Date/time datatype field mapping between XML Schema 1.0 and Java representation
   *       </th>
   *     </tr>
   *   </thead>
   *   <tbody>
   *     <tr>
   *       <th>XML Schema 1.0<br/>
   *           datatype<br/>
   *            field</th>
   *       <th>Related<br/>XMLGregorianCalendar<br/>Accessor(s)</th>
   *       <th>Value Range</th>
   *     </tr>
   *     <a name="datetimefield-year"/>
   *     <tr>
   *       <td> year </td>
   *       <td> {@link #getYear()} + {@link #getEon()} or<br/>
   *            {@link #getEonAndYear}
   *       </td>
   *       <td> <code>getYear()</code> is a value between -(10^9-1) to (10^9)-1
   *            or {@link DatatypeConstants#FIELD_UNDEFINED}.<br/>
   *            {@link #getEon()} is high order year value in billion of years.<br/>
   *            <code>getEon()</code> has values greater than or equal to (10^9) or less than or equal to -(10^9).
   *            A value of null indicates field is undefined.</br>
   *            Given that <a href="http://www.w3.org/2001/05/xmlschema-errata#e2-63">XML Schema 1.0 errata</a> states that the year zero
   *            will be a valid lexical value in a future version of XML Schema,
   *            this class allows the year field to be set to zero. Otherwise,
   *            the year field value is handled exactly as described
   *            in the errata and [ISO-8601-1988]. Note that W3C XML Schema 1.0
   *            validation does not allow for the year field to have a value of zero.
   *            </td>
   *     </tr>
   *     <a name="datetimefield-month"/>
   *     <tr>
   *       <td> month </td>
   *       <td> {@link #getMonth()} </td>
   *       <td> 1 to 12 or {@link DatatypeConstants#FIELD_UNDEFINED} </td>
   *     </tr>
   *     <a name="datetimefield-day"/>
   *     <tr>
   *       <td> day </td>
   *       <td> {@link #getDay()} </td>
   *       <td> Independent of month, max range is 1 to 31 or {@link DatatypeConstants#FIELD_UNDEFINED}.<br/>
   *            The normative value constraint stated relative to month
   *            field's value is in <a href="http://www.w3.org/TR/xmlschema-2/#isoformats">W3C XML Schema 1.0 Part 2, Appendix D</a>.
   *       </td>
   *     </tr>
   *     <a name="datetimefield-hour"/>
   *     <tr>
   *       <td> hour </td>
   *       <td> {@link #getHour()} </td>
   *       <td>
   *         0 to 23 or {@link DatatypeConstants#FIELD_UNDEFINED}.
   *         An hour value of 24 is allowed to be set in the lexical space provided the minute and second
   *         field values are zero. However, an hour value of 24 is not allowed in value space and will be
   *         transformed to represent the value of the first instance of the following day as per
   *         <a href="http://www.w3.org/TR/xmlschema-2/#built-in-primitive-datatypes">
   *         XML Schema Part 2: Datatypes Second Edition, 3.2 Primitive datatypes</a>.
   *       </td>
   *     </tr>
   *     <a name="datetimefield-minute"/>
   *     <tr>
   *       <td> minute </td>
   *       <td> {@link #getMinute()} </td>
   *       <td> 0 to 59 or {@link DatatypeConstants#FIELD_UNDEFINED} </td>
   *     </tr>
   *     <a name="datetimefield-second"/>
   *     <tr>
   *       <td>second</td>
   *       <td>
   *         {@link #getSecond()} + {@link #getMillisecond()}/1000 or<br/>
   *         {@link #getSecond()} + {@link #getFractionalSecond()}
   *       </td>
   *       <td>
   *         {@link #getSecond()} from 0 to 60 or {@link DatatypeConstants#FIELD_UNDEFINED}.<br/>
   *         <i>(Note: 60 only allowable for leap second.)</i><br/>
   *         {@link #getFractionalSecond()} allows for infinite precision over the range from 0.0 to 1.0 when
   *         the {@link #getSecond()} is defined.<br/>
   *         <code>FractionalSecond</code> is optional and has a value of <code>null</code> when it is undefined.<br />
   *            {@link #getMillisecond()} is the convenience
   *            millisecond precision of value of {@link #getFractionalSecond()}.
   *       </td>
   *     </tr>
   *     <tr id="datetimefield-timezone">
   *       <td> timezone </td>
   *       <td> {@link #getTimezone()} </td>
   *       <td> Number of minutes or {@link DatatypeConstants#FIELD_UNDEFINED}.
   *         Value range from -14 hours (-14 * 60 minutes) to 14 hours (14 * 60 minutes).
   *       </td>
   *     </tr>
   *   </tbody>
   *  </table>
   *
   * <p>All maximum value space constraints listed for the fields in the table
   * above are checked by factory methods, setter methods and parse methods of
   * this class. <code>IllegalArgumentException</code> is thrown when
   * parameter's value is outside the maximum value constraint for the field.
   * Validation checks, for example, whether days in month should be
   * limited to 29, 30 or 31 days, that are dependent on the values of other
   * fields are not checked by these methods.
   * </p>
   *
   * <p>The following operations are defined for this class:
   * <ul>
   *   <li>factory methods to create instances</li>
   *   <li>accessors/mutators for independent date/time fields</li>
   *   <li>conversion between this class and W3C XML Schema 1.0 lexical representation</li>
   *   <li>conversion between this class and <code>java.util.GregorianCalendar</code></li>
   *   <li>partial order relation comparator method, {@link #compare(XMLGregorianCalendar)}</li>
   *   <li>{@link #equals(Object)} defined relative to {@link #compare(XMLGregorianCalendar)}.</li>
   *   <li> addition operation with {@link Duration}.
   * instance as defined in <a href="http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes">
   * W3C XML Schema 1.0 Part 2, Appendix E, <i>Adding durations to dateTimes</i></a>.</li>
   * </ul>
   * </p>
   *
   * @author <a href="mailto:Kohsuke.Kawaguchi@Sun.com">Kohsuke Kawaguchi</a>
   * @author <a href="mailto:Joseph.Fialli@Sun.com">Joseph Fialli</a>
   * @author <a href="mailto:Sunitha.Reddy@Sun.com">Sunitha Reddy</a>
   * @version $Revision: 1.14 $, $Date: 2010-11-10 07:41:41 $
   * @see Duration
   * @since 1.5
   */
  
  public class XMLGregorianCalendarImpl
          extends XMLGregorianCalendar
          implements Serializable, Cloneable {
  
      /**
       * <p>Eon of this <code>XMLGregorianCalendar</code>.</p>
       */
      private BigInteger eon = null;
  
      /**
       * <p>Year of this <code>XMLGregorianCalendar</code>.</p>
       */
      private int year = DatatypeConstants.FIELD_UNDEFINED;
  
      /**
       * <p>Month of this <code>XMLGregorianCalendar</code>.</p>
       */
      private int month = DatatypeConstants.FIELD_UNDEFINED;
  
      /**
       * <p>Day of this <code>XMLGregorianCalendar</code>.</p>
       */
      private int day = DatatypeConstants.FIELD_UNDEFINED;
  
      /**
       * <p>Timezone of this <code>XMLGregorianCalendar</code> in minutes.</p>
       */
      private int timezone = DatatypeConstants.FIELD_UNDEFINED;
  
      /**
       * <p>Hour of this <code>XMLGregorianCalendar</code>.</p>
       */
      private int hour = DatatypeConstants.FIELD_UNDEFINED;
  
      /**
       * <p>Minute of this <code>XMLGregorianCalendar</code>.</p>
       */
      private int minute = DatatypeConstants.FIELD_UNDEFINED;
  
      /**
       * <p>Second of this <code>XMLGregorianCalendar</code>.</p>
       */
      private int second = DatatypeConstants.FIELD_UNDEFINED ;
  
      /**
       * <p>Fractional second of this <code>XMLGregorianCalendar</code>.</p>
       */
      private BigDecimal fractionalSecond = null;
  
      /**
       * <p>Constant to represent a billion.</p>
       */
      private static final BigInteger BILLION = new BigInteger("1000000000");
  
      /**
       *   <p>Obtain a pure Gregorian Calendar by calling
       *   GregorianCalendar.setChange(PURE_GREGORIAN_CHANGE). </p>
       */
      private static final Date PURE_GREGORIAN_CHANGE =
          new Date(Long.MIN_VALUE);
  
      /**
       * Year index for MIN_ and MAX_FIELD_VALUES.
       */
      private static final int YEAR   = 0;
  
      /**
       * Month index for MIN_ and MAX_FIELD_VALUES.
       */
      private static final int MONTH  = 1;
  
      /**
       * Day index for MIN_ and MAX_FIELD_VALUES.
       */
      private static final int DAY    = 2;
  
      /**
       * Hour index for MIN_ and MAX_FIELD_VALUES.
       */
      private static final int HOUR   = 3;
  
      /**
       * Minute index for MIN_ and MAX_FIELD_VALUES.
       */
      private static final int MINUTE = 4;
  
      /**
       * Second index for MIN_ and MAX_FIELD_VALUES.
       */
      private static final int SECOND = 5;
  
      /**
       * Second index for MIN_ and MAX_FIELD_VALUES.
       */
      private static final int MILLISECOND = 6;
  
      /**
       * Timezone index for MIN_ and MAX_FIELD_VALUES
       */
      private static final int TIMEZONE = 7;
  
  
      /**
       * field names indexed by YEAR..TIMEZONE.
       */
      private static final String FIELD_NAME[] = {
          "Year",
          "Month",
          "Day",
          "Hour",
          "Minute",
          "Second",
          "Millisecond",
          "Timezone"
      };
  
      /**
       * <p>Stream Unique Identifier.</p>
       *
       * <p>TODO: Serialization should use the XML string representation as
       * the serialization format to ensure future compatibility.</p>
       */
      private static final long serialVersionUID = 1L;
  
      /**
       * <p>Use as a template for default field values when
       * converting to a {@link GregorianCalendar}, set to a leap
       * year date of January 1, 0400 at midnight.</p>
       *
       * <p>Fields that are optional for an <code>xsd:dateTime</code> instances are defaulted to not being set to any value.
       * <code>XMLGregorianCalendar</code> fields millisecond, fractional second and timezone return the value indicating
       * that the field is not set, {@link DatatypeConstants#FIELD_UNDEFINED} for millisecond and timezone
       * and <code>null</code> for fractional second.</p>
       *
       * @see #toGregorianCalendar(TimeZone, Locale, XMLGregorianCalendar)
       */
      public static final XMLGregorianCalendar LEAP_YEAR_DEFAULT =
                  createDateTime(
                          400,  //year
                  DatatypeConstants.JANUARY,  //month
                          1,  // day
                      0,  // hour
                      0,  // minute
                      0,  // second
                      DatatypeConstants.FIELD_UNDEFINED,  // milliseconds
                      DatatypeConstants.FIELD_UNDEFINED // timezone
                  );
  
      // Constructors
  
      /**
       * Constructs a new XMLGregorianCalendar object.
       *
       * String parsing documented by {@link #parse(String)}.
       *
       * Returns a non-null valid XMLGregorianCalendar object that holds the
       * value indicated by the lexicalRepresentation parameter.
       *
       * @param lexicalRepresentation
       *      Lexical representation of one the eight
       *      XML Schema date/time datatypes.
       * @throws IllegalArgumentException
       *      If the given string does not conform as documented in
       *      {@link #parse(String)}.
       * @throws NullPointerException
       *      If the given string is null.
       */
      protected XMLGregorianCalendarImpl(String lexicalRepresentation)
              throws IllegalArgumentException {
  
          // compute format string for this lexical representation.
          String format = null;
          String lexRep = lexicalRepresentation;
          final int NOT_FOUND = -1;
          int lexRepLength = lexRep.length();
  
          // current parser needs a format string,
          // use following heuristics to figure out what xml schema date/time
          // datatype this lexical string could represent.
          // Fix 4971612: invalid SCCS macro substitution in data string,
          //   no %{alpha}% to avoid SCCS maco substitution
          if (lexRep.indexOf('T') != NOT_FOUND) {
              // found Date Time separater, must be xsd:DateTime
              format = "%Y-%M-%DT%h:%m:%s" + "%z";
          } else if (lexRepLength >= 3 && lexRep.charAt(2) == ':') {
              // found ":", must be xsd:Time
              format = "%h:%m:%s" + "%z";
          } else if (lexRep.startsWith("--")) {
              // check for gDay || gMonth || gMonthDay
              if (lexRepLength >= 3 && lexRep.charAt(2) == '-') {
                  // gDay, ---DD(z?)
                  format = "---%D" + "%z";
              } else if (lexRepLength == 4     // --MM
                      || lexRepLength == 5     // --MMZ
                      || lexRepLength == 10) { // --MMSHH:MM
                  // gMonth, --MM(z?),
                  // per XML Schema Errata, used to be --MM--(z?)
                  format = "--%M" + "%z";
              } else {
                  // gMonthDay, --MM-DD(z?), (or invalid lexicalRepresentation)
                  // length should be:
                  //  7: --MM-DD
                  //  8: --MM-DDZ
                  // 13: --MM-DDSHH:MM
                  format = "--%M-%D" + "%z";
              }
          } else {
              // check for Date || GYear | GYearMonth
              int countSeparator = 0;
  
              // start at index 1 to skip potential negative sign for year.
  
  
              int timezoneOffset = lexRep.indexOf(':');
              if (timezoneOffset != NOT_FOUND) {
  
                  // found timezone, strip it off for distinguishing
                  // between Date, GYear and GYearMonth so possible
                  // negative sign in timezone is not mistaken as
                  // a separator.
                  lexRepLength -= 6;
              }
  
              for (int i = 1; i < lexRepLength; i++) {
                  if (lexRep.charAt(i) == '-') {
                      countSeparator++;
                  }
              }
              if (countSeparator == 0) {
                  // GYear
                  format = "%Y" + "%z";
              } else if (countSeparator == 1) {
                  // GYearMonth
                  format = "%Y-%M" + "%z";
              } else {
                  // Date or invalid lexicalRepresentation
                  // Fix 4971612: invalid SCCS macro substitution in data string
                  format = "%Y-%M-%D" + "%z";
              }
          }
          Parser p = new Parser(format, lexRep);
          p.parse();
  
          // check for validity
          if (!isValid()) {
              throw new IllegalArgumentException(
                      DatatypeMessageFormatter.formatMessage(null, "InvalidXGCRepresentation", new Object[]{lexicalRepresentation})
                      //"\"" + lexicalRepresentation + "\" is not a valid representation of an XML Gregorian Calendar value."
              );
          }
      }
  
      /**
       * <p>Create an instance with all date/time datatype fields set to
       * {@link DatatypeConstants#FIELD_UNDEFINED} or null respectively.</p>
       */
      public XMLGregorianCalendarImpl() {
  
          // field initializers already do the correct initialization.
      }
  
      /**
       * <p>Private constructor allowing for complete value spaces allowed by
       * W3C XML Schema 1.0 recommendation for xsd:dateTime and related
       * builtin datatypes. Note that <code>year</code> parameter supports
       * arbitrarily large numbers and fractionalSecond has infinite
       * precision.</p>
       *
       * @param year of <code>XMLGregorianCalendar</code> to be created.
       * @param month of <code>XMLGregorianCalendar</code> to be created.
       * @param day of <code>XMLGregorianCalendar</code> to be created.
       * @param hour of <code>XMLGregorianCalendar</code> to be created.
       * @param minute of <code>XMLGregorianCalendar</code> to be created.
       * @param second of <code>XMLGregorianCalendar</code> to be created.
       * @param fractionalSecond of <code>XMLGregorianCalendar</code> to be created.
       * @param timezone of <code>XMLGregorianCalendar</code> to be created.
       *
       */
      protected XMLGregorianCalendarImpl(
          BigInteger year,
          int month,
          int day,
          int hour,
          int minute,
          int second,
          BigDecimal fractionalSecond,
          int timezone) {
  
                  setYear(year);
          setMonth(month);
          setDay(day);
          setTime(hour, minute, second, fractionalSecond);
                  setTimezone(timezone);
  
                  // check for validity
                  if (!isValid()) {
  
              throw new IllegalArgumentException(
                  DatatypeMessageFormatter.formatMessage(null,
                      "InvalidXGCValue-fractional",
                      new Object[] { year, new Integer(month), new Integer(day),
                      new Integer(hour), new Integer(minute), new Integer(second),
                      fractionalSecond, new Integer(timezone)})
                          );
  
                          /**
                  String yearString = "null";
                  if (year != null) {
                      yearString = year.toString();
                  }
                  String fractionalSecondString = "null";
                  if (fractionalSecond != null) {
                      fractionalSecondString = fractionalSecond.toString();
                  }
  
                  throw new IllegalArgumentException(
                      "year = " + yearString
                      + ", month = " + month
                      + ", day = " + day
                      + ", hour = " + hour
                      + ", minute = " + minute
                      + ", second = " + second
                      + ", fractionalSecond = " + fractionalSecondString
                      + ", timezone = " + timezone
                      + ", is not a valid representation of an XML Gregorian Calendar value."
                  );
                  */
  
                  }
  
      }
  
      /**
       * <p>Private constructor of value spaces that a
       * <code>java.util.GregorianCalendar</code> instance would need to convert to an
       * <code>XMLGregorianCalendar</code> instance.</p>
       *
       * <p><code>XMLGregorianCalendar eon</code> and
       * <code>fractionalSecond</code> are set to <code>null</code></p>
       *
       * @param year of <code>XMLGregorianCalendar</code> to be created.
       * @param month of <code>XMLGregorianCalendar</code> to be created.
       * @param day of <code>XMLGregorianCalendar</code> to be created.
       * @param hour of <code>XMLGregorianCalendar</code> to be created.
       * @param minute of <code>XMLGregorianCalendar</code> to be created.
       * @param second of <code>XMLGregorianCalendar</code> to be created.
       * @param millisecond of <code>XMLGregorianCalendar</code> to be created.
       * @param timezone of <code>XMLGregorianCalendar</code> to be created.
       */
      private XMLGregorianCalendarImpl(
          int year,
          int month,
          int day,
          int hour,
          int minute,
          int second,
                  int millisecond,
          int timezone) {
  
                  setYear(year);
          setMonth(month);
          setDay(day);
          setTime(hour, minute, second);
                  setTimezone(timezone);
                  setMillisecond(millisecond);
  
                  if (!isValid()) {
  
              throw new IllegalArgumentException(
                  DatatypeMessageFormatter.formatMessage(null,
                  "InvalidXGCValue-milli",
                  new Object[] { new Integer(year), new Integer(month), new Integer(day),
                  new Integer(hour), new Integer(minute), new Integer(second),
                  new Integer(millisecond), new Integer(timezone)})
                          );
                  /*
                  throw new IllegalArgumentException(
                      "year = " + year
                      + ", month = " + month
                      + ", day = " + day
                      + ", hour = " + hour
                      + ", minute = " + minute
                      + ", second = " + second
                      + ", millisecond = " + millisecond
                      + ", timezone = " + timezone
                      + ", is not a valid representation of an XML Gregorian Calendar value."
                      );
                   */
  
                  }
      }
  
          /**
           * <p>Convert a <code>java.util.GregorianCalendar</code> to XML Schema 1.0
           * representation.</p>
           *
           * <table border="2" rules="all" cellpadding="2">
           *   <thead>
           *     <tr>
           *       <th align="center" colspan="2">
           *          Field by Field Conversion from
           *          <code>java.util.GregorianCalendar</code> to this class
           *       </th>
           *     </tr>
           *   </thead>
           *   <tbody>
           *     <tr>
           *        <th><code>javax.xml.datatype.XMLGregorianCalendar</code> field</th>
           *        <th><code>java.util.GregorianCalendar</code> field</th>
           *     </tr>
           *     <tr>
           *       <th>{@link #setYear(int)}</th>
           *       <th><code>ERA == GregorianCalendar.BC ? -YEAR : YEAR</code></th>
           *     </tr>
           *     <tr>
           *       <th>{@link #setMonth(int)}</th>
           *       <th><code>MONTH + 1</code></th>
           *     </tr>
           *     <tr>
           *       <th>{@link #setDay(int)}</th>
           *       <th><code>DAY_OF_MONTH</code></th>
           *     </tr>
           *     <tr>
           *       <th>{@link #setTime(int,int,int, BigDecimal)}</th>
           *       <th><code>HOUR_OF_DAY, MINUTE, SECOND, MILLISECOND</code></th>
           *     </tr>
           *     <tr>
           *       <th>{@link #setTimezone(int)}<i>*</i></th>
           *       <th><code>(ZONE_OFFSET + DST_OFFSET) / (60*1000)</code><br/>
           *       <i>(in minutes)</i>
           *       </th>
           *     </tr>
           *   </tbody>
           * </table>
           * <p><i>*</i>conversion loss of information. It is not possible to represent
           * a <code>java.util.GregorianCalendar</code> daylight savings timezone id in the
           * XML Schema 1.0 date/time datatype representation.</p>
           *
           * <p>To compute the return value's <code>TimeZone</code> field,
           * <ul>
           * <li>when <code>this.getTimezone() != DatatypeConstants.FIELD_UNDEFINED</code>,
           * create a <code>java.util.TimeZone</code> with a custom timezone id
           * using the <code>this.getTimezone()</code>.</li>
           * <li>else use the <code>GregorianCalendar</code> default timezone value
           * for the host is defined as specified by
           * <code>java.util.TimeZone.getDefault()</code>.</li></p>
           *
           * @param cal <code>java.util.GregorianCalendar</code> used to create <code>XMLGregorianCalendar</code>
           */
      public XMLGregorianCalendarImpl(GregorianCalendar cal) {
  
          int year = cal.get(Calendar.YEAR);
          if (cal.get(Calendar.ERA) == GregorianCalendar.BC) {
              year = -year;
          }
          this.setYear(year);
  
          // Calendar.MONTH is zero based, XSD Date datatype's month field starts
          // with JANUARY as 1.
          this.setMonth(cal.get(Calendar.MONTH) + 1);
          this.setDay(cal.get(Calendar.DAY_OF_MONTH));
          this.setTime(
                  cal.get(Calendar.HOUR_OF_DAY),
                  cal.get(Calendar.MINUTE),
                  cal.get(Calendar.SECOND),
                  cal.get(Calendar.MILLISECOND));
  
          // Calendar ZONE_OFFSET and DST_OFFSET fields are in milliseconds.
          int offsetInMinutes = (cal.get(Calendar.ZONE_OFFSET) + cal.get(Calendar.DST_OFFSET)) / (60 * 1000);
          this.setTimezone(offsetInMinutes);
      }
  
      // Factories
  
      /**
       * <p>Create a Java representation of XML Schema builtin datatype <code>dateTime</code>.
       * All possible fields are specified for this factory method.</p>
       *
       * @param year represents both high-order eons and low-order year.
       * @param month of <code>dateTime</code>
       * @param day of <code>dateTime</code>
       * @param hours of <code>dateTime</code>
       * @param minutes of <code>dateTime</code>
       * @param seconds of <code>dateTime</code>
       * @param fractionalSecond value of null indicates optional field is absent.
       * @param timezone offset in minutes. {@link DatatypeConstants#FIELD_UNDEFINED} indicates optional field is not set.
       *
       * @return <code>XMLGregorianCalendar</code> created from parameter values.
       *
       * @see DatatypeConstants#FIELD_UNDEFINED
       *
       * @throws IllegalArgumentException if any parameter is outside value
       * constraints for the field as specified in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.
       */
      public static XMLGregorianCalendar createDateTime(
          BigInteger year,
          int month,
          int day,
          int hours,
          int minutes,
          int seconds,
          BigDecimal fractionalSecond,
          int timezone) {
  
          return new XMLGregorianCalendarImpl(
              year,
              month,
              day,
              hours,
              minutes,
              seconds,
              fractionalSecond,
              timezone);
      }
  
      /**
       * <p>Create a Java instance of XML Schema builtin datatype dateTime.</p>
       *
       * @param year represents both high-order eons and low-order year.
       * @param month of <code>dateTime</code>
       * @param day of <code>dateTime</code>
       * @param hour of <code>dateTime</code>
       * @param minute of <code>dateTime</code>
       * @param second of <code>dateTime</code>
       *
       * @return <code>XMLGregorianCalendar</code> created from parameter values.
       *
       * @throws IllegalArgumentException if any parameter is outside value constraints for the field as specified in
       *   <a href="#datetimefieldmapping">date/time field mapping table</a>.
       *
       * @see DatatypeConstants#FIELD_UNDEFINED
       */
      public static XMLGregorianCalendar createDateTime(
          int year,
          int month,
          int day,
          int hour,
          int minute,
          int second) {
  
          return new XMLGregorianCalendarImpl(
              year,
              month,
              day,
              hour,
              minute,
              second,
              DatatypeConstants.FIELD_UNDEFINED,  //millisecond
                  DatatypeConstants.FIELD_UNDEFINED //timezone
          );
      }
  
      /**
       * <p>Create a Java representation of XML Schema builtin datatype <code>dateTime</code>.
       * All possible fields are specified for this factory method.</p>
       *
       * @param year represents low-order year.
       * @param month of <code>dateTime</code>
       * @param day of <code>dateTime</code>
       * @param hours of <code>dateTime</code>
       * @param minutes of <code>dateTime</code>
       * @param seconds of <code>dateTime</code>
       * @param milliseconds of <code>dateTime</code>. {@link DatatypeConstants#FIELD_UNDEFINED} indicates optional field is not set.
       * @param timezone offset in minutes. {@link DatatypeConstants#FIELD_UNDEFINED} indicates optional field is not set.
       *
       * @return <code>XMLGregorianCalendar</code> created from parameter values.
       *
       * @throws IllegalArgumentException if any parameter is outside value constraints for the field as specified in
       *   <a href="#datetimefieldmapping">date/time field mapping table</a>.
       *
       * @see DatatypeConstants#FIELD_UNDEFINED
       */
      public static XMLGregorianCalendar createDateTime(
          int year,
          int month,
          int day,
          int hours,
          int minutes,
          int seconds,
          int milliseconds,
          int timezone) {
  
          return new XMLGregorianCalendarImpl(
              year,
              month,
              day,
              hours,
              minutes,
              seconds,
              milliseconds,
              timezone);
      }
  
      /**
       * <p>Create a Java representation of XML Schema builtin datatype <code>date</code> or <code>g*</code>.</p>
       *
       * <p>For example, an instance of <code>gYear</code> can be created invoking this factory
       * with <code>month</code> and <code>day</code> parameters set to
       * {@link DatatypeConstants#FIELD_UNDEFINED}.</p>
       *
       * @param year of <code>XMLGregorianCalendar</code> to be created.
       * @param month of <code>XMLGregorianCalendar</code> to be created.
       * @param day of <code>XMLGregorianCalendar</code> to be created.
       * @param timezone offset in minutes. {@link DatatypeConstants#FIELD_UNDEFINED} indicates optional field is not set.
       *
       * @return <code>XMLGregorianCalendar</code> created from parameter values.
       *
       * @see DatatypeConstants#FIELD_UNDEFINED
       *
       * @throws IllegalArgumentException if any parameter is outside value
       * constraints for the field as specified in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.
       */
      public static XMLGregorianCalendar createDate(
          int year,
          int month,
          int day,
          int timezone) {
  
          return new XMLGregorianCalendarImpl(
              year,
              month,
              day,
              DatatypeConstants.FIELD_UNDEFINED, // hour
              DatatypeConstants.FIELD_UNDEFINED, // minute
              DatatypeConstants.FIELD_UNDEFINED, // second
                  DatatypeConstants.FIELD_UNDEFINED, // millisecond
              timezone);
      }
  
      /**
       * Create a Java instance of XML Schema builtin datatype <code>time</code>.
       * @param hours number of hours
       * @param minutes number of minutes
       * @param seconds number of seconds
       * @param timezone offset in minutes. {@link DatatypeConstants#FIELD_UNDEFINED} indicates optional field is not set.
       *
       * @return <code>XMLGregorianCalendar</code> created from parameter values.
       *
       * @see DatatypeConstants#FIELD_UNDEFINED
       *
       * @throws IllegalArgumentException if any parameter is outside value
       * constraints for the field as specified in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.
       */
      public static XMLGregorianCalendar createTime(
          int hours,
          int minutes,
          int seconds,
                  int timezone) {
  
                  return new XMLGregorianCalendarImpl(
                          DatatypeConstants.FIELD_UNDEFINED, // Year
                          DatatypeConstants.FIELD_UNDEFINED, // Month
                          DatatypeConstants.FIELD_UNDEFINED, // Day
                          hours,
                          minutes,
                          seconds,
                          DatatypeConstants.FIELD_UNDEFINED, //Millisecond
                          timezone);
      }
  
      /**
       * <p>Create a Java instance of XML Schema builtin datatype time.</p>
       *
       * @param hours number of hours
       * @param minutes number of minutes
       * @param seconds number of seconds
       * @param fractionalSecond value of <code>null</code> indicates that this optional field is not set.
       * @param timezone offset in minutes. {@link DatatypeConstants#FIELD_UNDEFINED} indicates optional field is not set.
       *
       * @return <code>XMLGregorianCalendar</code> created from parameter values.
       *
       * @see DatatypeConstants#FIELD_UNDEFINED
       *
       * @throws IllegalArgumentException if any parameter is outside value
       * constraints for the field as specified in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.
       */
      public static XMLGregorianCalendar createTime(
          int hours,
          int minutes,
          int seconds,
          BigDecimal fractionalSecond,
          int timezone) {
  
          return new XMLGregorianCalendarImpl(
              null,            // Year
              DatatypeConstants.FIELD_UNDEFINED, // month
              DatatypeConstants.FIELD_UNDEFINED, // day
              hours,
              minutes,
              seconds,
              fractionalSecond,
              timezone);
      }
  
      /**
       * <p>Create a Java instance of XML Schema builtin datatype time.</p>
       *
       * @param hours number of hours
       * @param minutes number of minutes
       * @param seconds number of seconds
       * @param milliseconds number of milliseconds
       * @param timezone offset in minutes. {@link DatatypeConstants#FIELD_UNDEFINED} indicates optional field is not set.
       *
       * @return <code>XMLGregorianCalendar</code> created from parameter values.
       *
       * @see DatatypeConstants#FIELD_UNDEFINED
       *
       * @throws IllegalArgumentException if any parameter is outside value
       * constraints for the field as specified in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.
       */
      public static XMLGregorianCalendar createTime(
          int hours,
          int minutes,
          int seconds,
          int milliseconds,
          int timezone) {
  
          return new XMLGregorianCalendarImpl(
                  DatatypeConstants.FIELD_UNDEFINED, // year
                  DatatypeConstants.FIELD_UNDEFINED, // month
                  DatatypeConstants.FIELD_UNDEFINED, // day
                  hours,
                  minutes,
                  seconds,
                  milliseconds,
                  timezone);
      }
  
      // Accessors
  
      /**
       * <p>Return high order component for XML Schema 1.0 dateTime datatype field for
       * <code>year</code>.
       * <code>null</code> if this optional part of the year field is not defined.</p>
       *
       * <p>Value constraints for this value are summarized in
       * <a href="#datetimefield-year">year field of date/time field mapping table</a>.</p>
       * @return eon of this <code>XMLGregorianCalendar</code>. The value
       * returned is an integer multiple of 10^9.
       *
       * @see #getYear()
       * @see #getEonAndYear()
       */
      public BigInteger getEon() {
             return eon;
      }
  
      /**
       * <p>Return low order component for XML Schema 1.0 dateTime datatype field for
       * <code>year</code> or {@link DatatypeConstants#FIELD_UNDEFINED}.</p>
       *
       * <p>Value constraints for this value are summarized in
       * <a href="#datetimefield-year">year field of date/time field mapping table</a>.</p>
       *
       * @return year  of this <code>XMLGregorianCalendar</code>.
       *
       * @see #getEon()
       * @see #getEonAndYear()
       */
      public int getYear() {
             return year;
      }
  
      /**
       * <p>Return XML Schema 1.0 dateTime datatype field for
       * <code>year</code>.</p>
       *
       * <p>Value constraints for this value are summarized in
       * <a href="#datetimefield-year">year field of date/time field mapping table</a>.</p>
       *
       * @return sum of <code>eon</code> and <code>BigInteger.valueOf(year)</code>
       * when both fields are defined. When only <code>year</code> is defined,
       * return it. When both <code>eon</code> and <code>year</code> are not
       * defined, return <code>null</code>.
       *
       * @see #getEon()
       * @see #getYear()
       */
      public BigInteger getEonAndYear() {
  
                  // both are defined
                  if (year != DatatypeConstants.FIELD_UNDEFINED
                          && eon != null) {
  
                          return eon.add(BigInteger.valueOf((long) year));
                  }
  
                  // only year is defined
                  if (year != DatatypeConstants.FIELD_UNDEFINED
                          && eon == null) {
  
                          return BigInteger.valueOf((long) year);
                  }
  
          // neither are defined
          // or only eon is defined which is not valid without a year
                  return null;
      }
  
      /**
       * <p>Return number of month or {@link DatatypeConstants#FIELD_UNDEFINED}.</p>
       *
       * <p>Value constraints for this value are summarized in
       * <a href="#datetimefield-month">month field of date/time field mapping table</a>.</p>
       *
       * @return year  of this <code>XMLGregorianCalendar</code>.
       *
       */
      public int getMonth() {
          return month;
      }
  
      /**
       * Return day in month or {@link DatatypeConstants#FIELD_UNDEFINED}.</p>
       *
       * <p>Value constraints for this value are summarized in
       * <a href="#datetimefield-day">day field of date/time field mapping table</a>.</p>
       *
       * @see #setDay(int)
       */
      public int getDay() {
          return day;
      }
  
      /**
       * Return timezone offset in minutes or
       * {@link DatatypeConstants#FIELD_UNDEFINED} if this optional field is not defined.
       *
       * <p>Value constraints for this value are summarized in
       * <a href="#datetimefield-timezone">timezone field of date/time field mapping table</a>.</p>
       *
       * @see #setTimezone(int)
       */
      public int getTimezone() {
          return timezone;
      }
  
      /**
       * Return hours or {@link DatatypeConstants#FIELD_UNDEFINED}.
       * Returns {@link DatatypeConstants#FIELD_UNDEFINED} if this field is not defined.
       *
       * <p>Value constraints for this value are summarized in
       * <a href="#datetimefield-hour">hour field of date/time field mapping table</a>.</p>
       * @see #setTime(int, int, int)
       */
      public int getHour() {
          return hour;
      }
  
      /**
       * Return minutes or {@link DatatypeConstants#FIELD_UNDEFINED}.<\p>
       * Returns {@link DatatypeConstants#FIELD_UNDEFINED} if this field is not defined.
       *
       * <p>Value constraints for this value are summarized in
       * <a href="#datetimefield-minute">minute field of date/time field mapping table</a>.</p>
       * @see #setTime(int, int, int)
       */
      public int getMinute() {
          return minute;
      }
  
      /**
       * <p>Return seconds or {@link DatatypeConstants#FIELD_UNDEFINED}.<\p>
       *
       * <p>Returns {@link DatatypeConstants#FIELD_UNDEFINED} if this field is not defined.
       * When this field is not defined, the optional xs:dateTime
       * fractional seconds field, represented by
       * {@link #getFractionalSecond()} and {@link #getMillisecond()},
       * must not be defined.</p>
       *
       * <p>Value constraints for this value are summarized in
       * <a href="#datetimefield-second">second field of date/time field mapping table</a>.</p>
       *
       * @return Second  of this <code>XMLGregorianCalendar</code>.
       *
       * @see #getFractionalSecond()
       * @see #getMillisecond()
       * @see #setTime(int, int, int)
       */
      public int getSecond() {
             return second;
      }
  
      /**
       * @return result of adding second and fractional second field
       */
      private BigDecimal getSeconds() {
          if (second == DatatypeConstants.FIELD_UNDEFINED) {
              return DECIMAL_ZERO;
          }
          BigDecimal result = BigDecimal.valueOf((long) second);
          if (fractionalSecond != null) {
              return result.add(fractionalSecond);
          } else {
              return result;
          }
      }
  
  
      /**
       * <p>Return millisecond precision of {@link #getFractionalSecond()}.<\p>
       *
       * <p>This method represents a convenience accessor to infinite
       * precision fractional second value returned by
       * {@link #getFractionalSecond()}. The returned value is the rounded
       * down to milliseconds value of
       * {@link #getFractionalSecond()}. When {@link #getFractionalSecond()}
       * returns <code>null</code>, this method must return
       * {@link DatatypeConstants#FIELD_UNDEFINED}.</p>
       *
       * <p>Value constraints for this value are summarized in
       * <a href="#datetimefield-second">second field of date/time field mapping table</a>.</p>
       *
       * @return Millisecond  of this <code>XMLGregorianCalendar</code>.
       *
       * @see #getFractionalSecond()
       * @see #setTime(int, int, int)
       */
      public int getMillisecond() {
          if (fractionalSecond == null) {
              return DatatypeConstants.FIELD_UNDEFINED;
          } else {
              // TODO: Non-optimal solution for now.
              // Efficient implementation would only store as BigDecimal
              // when needed and millisecond otherwise.
              return fractionalSecond.movePointRight(3).intValue();
          }
      }
  
      /**
       * <p>Return fractional seconds.</p>
       *
       * <p><code>null</code> is returned when this optional field is not defined.</p>
       *
       * <p>Value constraints are detailed in
       * <a href="#datetimefield-second">second field of date/time field mapping table</a>.</p>
       *
       * <p>This optional field can only have a defined value when the
       * xs:dateTime second field, represented by ({@link #getSecond()},
       * does not return {@link DatatypeConstants#FIELD_UNDEFINED}).</p>
       *
       * @return fractional seconds  of this <code>XMLGregorianCalendar</code>.
       *
       * @see #getSecond()
       * @see #setTime(int, int, int, BigDecimal)
       */
      public BigDecimal getFractionalSecond() {
             return fractionalSecond;
      }
  
      // setters
  
      /**
       * <p>Set low and high order component of XSD <code>dateTime</code> year field.</p>
       *
       * <p>Unset this field by invoking the setter with a parameter value of <code>null</code>.</p>
       *
       * @param year value constraints summarized in <a href="#datetimefield-year">year field of date/time field mapping table</a>.
       *
       * @throws IllegalArgumentException if <code>year</code> parameter is
       * outside value constraints for the field as specified in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.
       */
      public void setYear(BigInteger year) {
          if (year == null) {
              this.eon = null;
              this.year = DatatypeConstants.FIELD_UNDEFINED;
          } else {
              BigInteger temp = year.remainder(BILLION);
              this.year = temp.intValue();
              setEon(year.subtract(temp));
          }
      }
  
      /**
       * <p>Set year of XSD <code>dateTime</code> year field.</p>
       *
       * <p>Unset this field by invoking the setter with a parameter value of
       * {@link DatatypeConstants#FIELD_UNDEFINED}.</p>
       *
       * <p>Note: if the absolute value of the <code>year</code> parameter
       * is less than 10^9, the eon component of the XSD year field is set to
       * <code>null</code> by this method.</p>
       *
       * @param year value constraints are summarized in <a href="#datetimefield-year">year field of date/time field mapping table</a>.
       *   If year is {@link DatatypeConstants#FIELD_UNDEFINED}, then eon is set to <code>null</code>.
       */
      public void setYear(int year) {
          if (year == DatatypeConstants.FIELD_UNDEFINED) {
              this.year = DatatypeConstants.FIELD_UNDEFINED;
              this.eon = null;
          } else if (Math.abs(year) < BILLION.intValue()) {
              this.year = year;
              this.eon = null;
          } else {
              BigInteger theYear = BigInteger.valueOf((long) year);
              BigInteger remainder = theYear.remainder(BILLION);
              this.year = remainder.intValue();
              setEon(theYear.subtract(remainder));
          }
      }
  
      /**
       * <p>Set high order part of XSD <code>dateTime</code> year field.</p>
       *
       * <p>Unset this field by invoking the setter with a parameter value of
       * <code>null</code>.</p>
       *
       * @param eon value constraints summarized in <a href="#datetimefield-year">year field of date/time field mapping table</a>.
       */
      private void setEon(BigInteger eon) {
          if (eon != null && eon.compareTo(BigInteger.ZERO) == 0) {
              // Treat ZERO as field being undefined.
              this.eon = null;
          } else {
              this.eon = eon;
          }
      }
  
      /**
       * <p>Set month.</p>
       *
       * <p>Unset this field by invoking the setter with a parameter value of {@link DatatypeConstants#FIELD_UNDEFINED}.</p>
       *
       * @param month value constraints summarized in <a href="#datetimefield-month">month field of date/time field mapping table</a>.
       *
       * @throws IllegalArgumentException if <code>month</code> parameter is
       * outside value constraints for the field as specified in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.
       */
      public void setMonth(int month) {
          if(month<DatatypeConstants.JANUARY || DatatypeConstants.DECEMBER<month)
              if(month!=DatatypeConstants.FIELD_UNDEFINED)
                  invalidFieldValue(MONTH, month);
          this.month = month;
      }
  
      /**
       * <p>Set days in month.</p>
       *
       * <p>Unset this field by invoking the setter with a parameter value of {@link DatatypeConstants#FIELD_UNDEFINED}.</p>
       *
       * @param day value constraints summarized in <a href="#datetimefield-day">day field of date/time field mapping table</a>.
       *
       * @throws IllegalArgumentException if <code>day</code> parameter is
       * outside value constraints for the field as specified in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.
       */
      public void setDay(int day) {
          if(day<1 || 31<day)
              if(day!=DatatypeConstants.FIELD_UNDEFINED)
                  invalidFieldValue(DAY,day);
          this.day = day;
      }
  
      /**
       * <p>Set the number of minutes in the timezone offset.</p>
       *
       * <p>Unset this field by invoking the setter with a parameter value of {@link DatatypeConstants#FIELD_UNDEFINED}.</p>
       *
       * @param offset value constraints summarized in <a href="#datetimefield-timezone">
       *   timezone field of date/time field mapping table</a>.
       *
       * @throws IllegalArgumentException if <code>offset</code> parameter is
       * outside value constraints for the field as specified in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.
       */
      public void setTimezone(int offset) {
              if(offset<-14*60 || 14*60<offset)
              if(offset!=DatatypeConstants.FIELD_UNDEFINED)
                  invalidFieldValue(TIMEZONE,offset);
          this.timezone = offset;
      }
  
      /**
       * <p>Set time as one unit.</p>
       *
       * @param hour value constraints are summarized in
       * <a href="#datetimefield-hour">hour field of date/time field mapping table</a>.
       * @param minute value constraints are summarized in
       * <a href="#datetimefield-minute">minute field of date/time field mapping table</a>.
       * @param second value constraints are summarized in
       * <a href="#datetimefield-second">second field of date/time field mapping table</a>.
       *
       * @see #setTime(int, int, int, BigDecimal)
       *
       * @throws IllegalArgumentException if any parameter is
       * outside value constraints for the field as specified in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.
       */
      public void setTime(int hour, int minute, int second) {
          setTime(hour, minute, second, null);
      }
  
      private void invalidFieldValue(int field, int value) {
          throw new IllegalArgumentException(
              DatatypeMessageFormatter.formatMessage(null, "InvalidFieldValue",
                  new Object[]{ new Integer(value), FIELD_NAME[field]})
          );
      }
  
      private void testHour() {
  
          // http://www.w3.org/2001/05/xmlschema-errata#e2-45
          if (getHour() == 24) {
              if (getMinute() != 0
                      || getSecond() != 0) {
                  invalidFieldValue(HOUR, getHour());
              }
              // while 0-24 is acceptable in the lexical space, 24 is not valid in value space
              // W3C XML Schema Part 2, Section 3.2.7.1
              setHour(0, false);
              add(new DurationImpl(true, 0, 0, 1, 0, 0, 0));
          }
      }
  
      public void setHour(int hour) {
  
          setHour(hour, true);
      }
  
      private void setHour(int hour, boolean validate) {
  
          if (hour < 0 || hour > 24) {
              if (hour != DatatypeConstants.FIELD_UNDEFINED) {
                  invalidFieldValue(HOUR, hour);
              }
          }
  
          this.hour = hour;
  
          if (validate) {
              testHour();
          }
      }
  
      public void setMinute(int minute) {
          if(minute<0 || 59<minute)
              if(minute!=DatatypeConstants.FIELD_UNDEFINED)
                  invalidFieldValue(MINUTE, minute);
          this.minute = minute;
      }
  
      public void setSecond(int second) {
          if(second<0 || 60<second)   // leap second allows for 60
              if(second!=DatatypeConstants.FIELD_UNDEFINED)
                  invalidFieldValue(SECOND, second);
          this.second  = second;
      }
  
      /**
       * <p>Set time as one unit, including the optional infinite precison
       * fractional seconds.</p>
       *
       * @param hour value constraints are summarized in
       * <a href="#datetimefield-hour">hour field of date/time field mapping table</a>.
       * @param minute value constraints are summarized in
       * <a href="#datetimefield-minute">minute field of date/time field mapping table</a>.
       * @param second value constraints are summarized in
       * <a href="#datetimefield-second">second field of date/time field mapping table</a>.
       * @param fractional value of <code>null</code> indicates this optional
       *                   field is not set.
       *
       * @throws IllegalArgumentException if any parameter is
       * outside value constraints for the field as specified in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.
       */
      public void setTime(
              int hour,
              int minute,
              int second,
              BigDecimal fractional) {
  
          setHour(hour, false);
  
          setMinute(minute);
          if (second != 60) {
              setSecond(second);
          } else if ((hour == 23 && minute == 59) || (hour == 0 && minute == 0)) {
              setSecond(second);
          } else {
              invalidFieldValue(SECOND, second);
          }
  
          setFractionalSecond(fractional);
  
          // must test hour after setting seconds
          testHour();
      }
  
  
      /**
       * <p>Set time as one unit, including optional milliseconds.</p>
       *
       * @param hour value constraints are summarized in
       * <a href="#datetimefield-hour">hour field of date/time field mapping table</a>.
       * @param minute value constraints are summarized in
       * <a href="#datetimefield-minute">minute field of date/time field mapping table</a>.
       * @param second value constraints are summarized in
       * <a href="#datetimefield-second">second field of date/time field mapping table</a>.
       * @param millisecond value of {@link DatatypeConstants#FIELD_UNDEFINED} indicates this
       *                    optional field is not set.
       *
       * @throws IllegalArgumentException if any parameter is
       * outside value constraints for the field as specified in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.
       */
      public void setTime(int hour, int minute, int second, int millisecond) {
  
          setHour(hour, false);
  
          setMinute(minute);
          if (second != 60) {
              setSecond(second);
          } else if ((hour == 23 && minute == 59) || (hour == 0 && minute == 0)) {
              setSecond(second);
          } else {
              invalidFieldValue(SECOND, second);
          }
          setMillisecond(millisecond);
  
          // must test hour after setting seconds
          testHour();
      }
  
      // comparisons
      /**
       * <p>Compare two instances of W3C XML Schema 1.0 date/time datatypes
       * according to partial order relation defined in
       * <a href="http://www.w3.org/TR/xmlschema-2/#dateTime-order">W3C XML Schema 1.0 Part 2, Section 3.2.7.3,
       * <i>Order relation on dateTime</i></a>.</p>
       *
       * <p><code>xsd:dateTime</code> datatype field mapping to accessors of
       * this class are defined in
       * <a href="#datetimefieldmapping">date/time field mapping table</a>.</p>
       *
       * @param rhs instance of <code>XMLGregorianCalendar</code> to compare
       *
       * @return the relationship between <code>lhs</code> and <code>rhs</code> as
       *   {@link DatatypeConstants#LESSER},
       *   {@link DatatypeConstants#EQUAL},
       *   {@link DatatypeConstants#GREATER} or
       *   {@link DatatypeConstants#INDETERMINATE}.
       *
       * @throws NullPointerException if <code>lhs</code> or <code>rhs</code>
       * parameters are null.
       */
      public int compare(XMLGregorianCalendar rhs) {
  
          XMLGregorianCalendar lhs = this;
  
          int result = DatatypeConstants.INDETERMINATE;
          XMLGregorianCalendarImpl P = (XMLGregorianCalendarImpl) lhs;
          XMLGregorianCalendarImpl Q = (XMLGregorianCalendarImpl) rhs;
  
          if (P.getTimezone() == Q.getTimezone()) {
              // Optimization:
              // both instances are in same timezone or
              // both are FIELD_UNDEFINED.
              // Avoid costly normalization of timezone to 'Z' time.
              return internalCompare(P, Q);
  
          } else if (P.getTimezone() != DatatypeConstants.FIELD_UNDEFINED &&
                  Q.getTimezone() != DatatypeConstants.FIELD_UNDEFINED) {
  
              // Both instances have different timezones.
              // Normalize to UTC time and compare.
              P = (XMLGregorianCalendarImpl) P.normalize();
              Q = (XMLGregorianCalendarImpl) Q.normalize();
              return internalCompare(P, Q);
          } else if (P.getTimezone() != DatatypeConstants.FIELD_UNDEFINED) {
  
              if (P.getTimezone() != 0) {
                  P = (XMLGregorianCalendarImpl) P.normalize();
              }
  
              // C. step 1
              XMLGregorianCalendar MinQ = Q.normalizeToTimezone(DatatypeConstants.MIN_TIMEZONE_OFFSET);
              result = internalCompare(P, MinQ);
              if (result == DatatypeConstants.LESSER) {
                  return result;
              }
  
              // C. step 2
              XMLGregorianCalendar MaxQ = Q.normalizeToTimezone(DatatypeConstants.MAX_TIMEZONE_OFFSET);
              result = internalCompare(P, MaxQ);
              if (result == DatatypeConstants.GREATER) {
                  return result;
              } else {
                  // C. step 3
                  return DatatypeConstants.INDETERMINATE;
              }
          } else { // Q.getTimezone() != DatatypeConstants.FIELD_UNDEFINED
              // P has no timezone and Q does.
              if (Q.getTimezone() != 0) {
                  Q = (XMLGregorianCalendarImpl) Q.normalizeToTimezone(Q.getTimezone());
              }
  
              // D. step 1
              XMLGregorianCalendar MaxP = P.normalizeToTimezone(DatatypeConstants.MAX_TIMEZONE_OFFSET);
              result = internalCompare(MaxP, Q);
              if (result == DatatypeConstants.LESSER) {
                  return result;
              }
  
              // D. step 2
              XMLGregorianCalendar MinP = P.normalizeToTimezone(DatatypeConstants.MIN_TIMEZONE_OFFSET);
              result = internalCompare(MinP, Q);
              if (result == DatatypeConstants.GREATER) {
                  return result;
              } else {
                  // D. step 3
                  return DatatypeConstants.INDETERMINATE;
              }
          }
      }
  
      /**
       * <p>Normalize this instance to UTC.</p>
       *
       * <p>2000-03-04T23:00:00+03:00 normalizes to 2000-03-04T20:00:00Z</p>
       * <p>Implements W3C XML Schema Part 2, Section 3.2.7.3 (A).</p>
       */
      public XMLGregorianCalendar normalize() {
  
          XMLGregorianCalendar normalized = normalizeToTimezone(timezone);
  
          // if timezone was undefined, leave it undefined
          if (getTimezone() == DatatypeConstants.FIELD_UNDEFINED) {
              normalized.setTimezone(DatatypeConstants.FIELD_UNDEFINED);
          }
  
          // if milliseconds was undefined, leave it undefined
          if (getMillisecond() == DatatypeConstants.FIELD_UNDEFINED) {
              normalized.setMillisecond(DatatypeConstants.FIELD_UNDEFINED);
          }
  
          return normalized;
      }
  
          /**
           * <p>Normalize this instance to UTC.</p>
           *
           * <p>2000-03-04T23:00:00+03:00 normalizes to 2000-03-04T20:00:00Z</p>
           * <p>Implements W3C XML Schema Part 2, Section 3.2.7.3 (A).</p>
           */
      private XMLGregorianCalendar normalizeToTimezone(int timezone) {
  
          int minutes = timezone;
          XMLGregorianCalendar result = (XMLGregorianCalendar) this.clone();
  
          // normalizing to UTC time negates the timezone offset before
          // addition.
          minutes = -minutes;
          Duration d = new DurationImpl(minutes >= 0, // isPositive
                  0, //years
                  0, //months
                  0, //days
                  0, //hours
                  minutes < 0 ? -minutes : minutes, // absolute
                  0  //seconds
          );
          result.add(d);
  
          // set to zulu UTC time.
          result.setTimezone(0);
          return result;
      }
  
      /**
       *
       *  <p>Implements Step B from http://www.w3.org/TR/xmlschema-2/#dateTime-order </p>
       * @param P calendar instance with normalized timezone offset or
       *          having same timezone as Q
       * @param Q calendar instance with normalized timezone offset or
       *          having same timezone as P
       *
       * @return result of comparing P and Q, value of
       *   {@link DatatypeConstants#EQUAL},
       *   {@link DatatypeConstants#LESSER},
       *   {@link DatatypeConstants#GREATER} or
       *   {@link DatatypeConstants#INDETERMINATE}.
       */
      private static int internalCompare(XMLGregorianCalendar P,
                                         XMLGregorianCalendar Q) {
  
          int result;
  
          // compare Year.
          if (P.getEon() == Q.getEon()) {
  
              // Eon field is only equal when null.
              // optimized case for comparing year not requiring eon field.
              result = compareField(P.getYear(), Q.getYear());
              if (result != DatatypeConstants.EQUAL) {
                  return result;
              }
          } else {
              result = compareField(P.getEonAndYear(), Q.getEonAndYear());
              if (result != DatatypeConstants.EQUAL) {
                  return result;
              }
          }
  
          result = compareField(P.getMonth(), Q.getMonth());
          if (result != DatatypeConstants.EQUAL) {
              return result;
          }
  
          result = compareField(P.getDay(), Q.getDay());
          if (result != DatatypeConstants.EQUAL) {
              return result;
          }
  
          result = compareField(P.getHour(), Q.getHour());
          if (result != DatatypeConstants.EQUAL) {
              return result;
          }
  
          result = compareField(P.getMinute(), Q.getMinute());
          if (result != DatatypeConstants.EQUAL) {
              return result;
          }
          result = compareField(P.getSecond(), Q.getSecond());
          if (result != DatatypeConstants.EQUAL) {
              return result;
          }
  
          result = compareField(P.getFractionalSecond(), Q.getFractionalSecond());
          return result;
      }
  
      /**
       * <p>Implement Step B from
       * http://www.w3.org/TR/xmlschema-2/#dateTime-order.</p>
       */
      private static int compareField(int Pfield, int Qfield) {
          if (Pfield == Qfield) {
  
              //fields are either equal in value or both undefined.
              // Step B. 1.1 AND optimized result of performing 1.1-1.4.
              return DatatypeConstants.EQUAL;
          } else {
              if (Pfield == DatatypeConstants.FIELD_UNDEFINED || Qfield == DatatypeConstants.FIELD_UNDEFINED) {
                  // Step B. 1.2
                  return DatatypeConstants.INDETERMINATE;
              } else {
                  // Step B. 1.3-4.
                  return (Pfield < Qfield ? DatatypeConstants.LESSER : DatatypeConstants.GREATER);
              }
          }
      }
  
      private static int compareField(BigInteger Pfield, BigInteger Qfield) {
          if (Pfield == null) {
              return (Qfield == null ? DatatypeConstants.EQUAL : DatatypeConstants.INDETERMINATE);
          }
          if (Qfield == null) {
              return DatatypeConstants.INDETERMINATE;
          }
          return Pfield.compareTo(Qfield);
      }
  
      private static int compareField(BigDecimal Pfield, BigDecimal Qfield) {
          // optimization. especially when both arguments are null.
          if (Pfield == Qfield) {
              return DatatypeConstants.EQUAL;
          }
  
          if (Pfield == null) {
              Pfield = DECIMAL_ZERO;
          }
  
          if (Qfield == null) {
              Qfield = DECIMAL_ZERO;
          }
  
          return Pfield.compareTo(Qfield);
      }
  
      /**
       * <p>Indicates whether parameter <code>obj</code> is "equal to" this one.</p>
       *
       * @param obj to compare.
       *
       * @return <code>true</code> when <code>compare(this,(XMLGregorianCalendar)obj) == EQUAL.</code>.
       */
      public boolean equals(Object obj) {
  
          if (obj == null || !(obj instanceof XMLGregorianCalendar)) {
              return false;
          }
          return compare((XMLGregorianCalendar) obj) == DatatypeConstants.EQUAL;
      }
  
      /**
       * <p>Returns a hash code consistent with the definition of the equals method.</p>
       *
       * @return hash code of this object.
       */
      public int hashCode() {
  
          // Following two dates compare to EQUALS since in different timezones.
          // 2000-01-15T12:00:00-05:00 == 2000-01-15T13:00:00-04:00
          //
          // Must ensure both instances generate same hashcode by normalizing
          // this to UTC timezone.
          int timezone = getTimezone();
          if (timezone == DatatypeConstants.FIELD_UNDEFINED) {
              timezone = 0;
          }
          XMLGregorianCalendar gc = this;
          if (timezone != 0) {
              gc = this.normalizeToTimezone(getTimezone());
          }
          return gc.getYear() + gc.getMonth() + gc.getDay() +
                  gc.getHour() + gc.getMinute() + gc.getSecond();
      }
  
  
      /**
       * <p>Constructs a new XMLGregorianCalendar object by
       * parsing its lexical string representation as defined in
       * <a href="http://www.w3.org/TR/xmlschema-2/#dateTime-order">XML Schema 1.0 Part 2, Section 3.2.[7-14].1,
       * <i>Lexical Representation</i>.</a></p>
       *
       * <p>The string representation may not have any leading and trailing whitespaces.</p>
       *
       * <p>The parsing is done field by field so that
       * the following holds for any lexically correct string x:</p>
       * <pre>
       * new XMLGregorianCalendar(x).toXMLFormat().equals(x)
       * </pre>
       * Except for the noted lexical/canonical representation mismatches
       * listed in <a href="http://www.w3.org/2001/05/xmlschema-errata#e2-45">
       * XML Schema 1.0 errata, Section 3.2.7.2</a>.
       *
       * <p>Returns a non-null valid XMLGregorianCalendar object that holds the value
       * indicated by the lexicalRepresentation parameter.</p>
       *
       * @param lexicalRepresentation Lexical representation of one the 8 XML Schema calendar datatypes.
       *
       * @return <code>XMLGregorianCalendar</code> created from parsing <code>lexicalRepresentation</code> parameter.
       *
       * @throws IllegalArgumentException
       *      If the given string does not conform to the aforementioned
       *      specification.
       * @throws NullPointerException
       *      If the given string is null.
       */
      public static XMLGregorianCalendar parse(String lexicalRepresentation) {
  
                  return new XMLGregorianCalendarImpl(lexicalRepresentation);
      }
  
      /**
       * <p>Return the lexical representation of <code>this</code> instance.
       * The format is specified in
       * <a href="http://www.w3.org/TR/xmlschema-2/#dateTime-order">XML Schema 1.0 Part 2, Section 3.2.[7-14].1,
       * <i>Lexical Representation</i>".</a></p>
       *
       * <p>Specific target lexical representation format is determined by
       * {@link #getXMLSchemaType()}.</p>
       *
       * @return XML, as <code>String</code>, representation of this <code>XMLGregorianCalendar</code>
       *
       * @throws java.lang.IllegalStateException if the combination of set fields
       *    does not match one of the eight defined XML Schema builtin date/time datatypes.
       */
      public String toXMLFormat() {
  
          QName typekind = getXMLSchemaType();
  
          String formatString = null;
          // Fix 4971612: invalid SCCS macro substitution in data string
          //   no %{alpha}% to avoid SCCS macro substitution
          if (typekind == DatatypeConstants.DATETIME) {
              formatString = "%Y-%M-%DT%h:%m:%s" + "%z";
          } else if (typekind == DatatypeConstants.DATE) {
              formatString = "%Y-%M-%D" + "%z";
          } else if (typekind == DatatypeConstants.TIME) {
              formatString = "%h:%m:%s" + "%z";
          } else if (typekind == DatatypeConstants.GMONTH) {
              formatString = "--%M" + "%z";
          } else if (typekind == DatatypeConstants.GDAY) {
              formatString = "---%D" + "%z";
          } else if (typekind == DatatypeConstants.GYEAR) {
              formatString = "%Y" + "%z";
          } else if (typekind == DatatypeConstants.GYEARMONTH) {
              formatString = "%Y-%M" + "%z";
          } else if (typekind == DatatypeConstants.GMONTHDAY) {
              formatString = "--%M-%D" + "%z";
          }
          return format(formatString);
      }
  
      /**
       * <p>Return the name of the XML Schema date/time type that this instance
       * maps to. Type is computed based on fields that are set.</p>
       *
       * <table border="2" rules="all" cellpadding="2">
       *   <thead>
       *     <tr>
       *       <th align="center" colspan="7">
       *         Required fields for XML Schema 1.0 Date/Time Datatypes.<br/>
       *         <i>(timezone is optional for all date/time datatypes)</i>
       *       </th>
       *     </tr>
       *   </thead>
       *   <tbody>
       *     <tr>
       *       <td>Datatype</td>
       *       <td>year</td>
       *       <td>month</td>
       *       <td>day</td>
       *       <td>hour</td>
       *       <td>minute</td>
       *       <td>second</td>
       *     </tr>
       *     <tr>
       *       <td>{@link DatatypeConstants#DATETIME}</td>
       *       <td>X</td>
       *       <td>X</td>
       *       <td>X</td>
       *       <td>X</td>
       *       <td>X</td>
       *       <td>X</td>
       *     </tr>
       *     <tr>
       *       <td>{@link DatatypeConstants#DATE}</td>
       *       <td>X</td>
       *       <td>X</td>
       *       <td>X</td>
       *       <td></td>
       *       <td></td>
       *       <td></td>
       *     </tr>
       *     <tr>
       *       <td>{@link DatatypeConstants#TIME}</td>
       *       <td></td>
       *       <td></td>
       *       <td></td>
       *       <td>X</td>
       *       <td>X</td>
       *       <td>X</td>
       *     </tr>
       *     <tr>
       *       <td>{@link DatatypeConstants#GYEARMONTH}</td>
       *       <td>X</td>
       *       <td>X</td>
       *       <td></td>
       *       <td></td>
       *       <td></td>
       *       <td></td>
       *     </tr>
       *     <tr>
       *       <td>{@link DatatypeConstants#GMONTHDAY}</td>
       *       <td></td>
       *       <td>X</td>
       *       <td>X</td>
       *       <td></td>
       *       <td></td>
       *       <td></td>
       *     </tr>
       *     <tr>
       *       <td>{@link DatatypeConstants#GYEAR}</td>
       *       <td>X</td>
       *       <td></td>
       *       <td></td>
       *       <td></td>
       *       <td></td>
       *       <td></td>
       *     </tr>
       *     <tr>
       *       <td>{@link DatatypeConstants#GMONTH}</td>
       *       <td></td>
       *       <td>X</td>
       *       <td></td>
       *       <td></td>
       *       <td></td>
       *       <td></td>
       *     </tr>
       *     <tr>
       *       <td>{@link DatatypeConstants#GDAY}</td>
       *       <td></td>
       *       <td></td>
       *       <td>X</td>
       *       <td></td>
       *       <td></td>
       *       <td></td>
       *     </tr>
       *   </tbody>
       * </table>
       *
       * @throws java.lang.IllegalStateException if the combination of set fields
       *    does not match one of the eight defined XML Schema builtin
       *    date/time datatypes.
       * @return One of the following class constants:
       *   {@link DatatypeConstants#DATETIME},
       *   {@link DatatypeConstants#TIME},
       *   {@link DatatypeConstants#DATE},
       *   {@link DatatypeConstants#GYEARMONTH},
       *   {@link DatatypeConstants#GMONTHDAY},
       *   {@link DatatypeConstants#GYEAR},
       *   {@link DatatypeConstants#GMONTH} or
       *   {@link DatatypeConstants#GDAY}.
       */
      public QName getXMLSchemaType() {
  
          int mask =
              (year != DatatypeConstants.FIELD_UNDEFINED ?   0x20 : 0 )|
              (month != DatatypeConstants.FIELD_UNDEFINED ?  0x10 : 0 )|
              (day != DatatypeConstants.FIELD_UNDEFINED ?    0x08 : 0 )|
              (hour != DatatypeConstants.FIELD_UNDEFINED ?   0x04 : 0 )|
              (minute != DatatypeConstants.FIELD_UNDEFINED ? 0x02 : 0 )|
              (second != DatatypeConstants.FIELD_UNDEFINED ? 0x01 : 0 );
  
          switch(mask) {
          case 0x3F:
                  return DatatypeConstants.DATETIME;
          case 0x38:
                  return DatatypeConstants.DATE;
          case 0x07:
                  return DatatypeConstants.TIME;
          case 0x30:
                  return DatatypeConstants.GYEARMONTH;
          case 0x18:
                  return DatatypeConstants.GMONTHDAY;
          case 0x20:
                  return DatatypeConstants.GYEAR;
          case 0x10:
                  return DatatypeConstants.GMONTH;
          case 0x08:
                  return DatatypeConstants.GDAY;
          default:
              throw new IllegalStateException(
                  this.getClass().getName()
                  + "#getXMLSchemaType() :"
                  + DatatypeMessageFormatter.formatMessage(null, "InvalidXGCFields", null)
              );
          }
      }
  
  
      /**
       * Validate instance by <code>getXMLSchemaType()</code> constraints.
       * @return true if data values are valid.
       */
      public boolean isValid() {
          // since setters do not allow for invalid values,
          // (except for exceptional case of year field of zero),
          // no need to check for anything except for constraints
          // between fields.
  
          //check if days in month is valid. Can be dependent on leap year.
          if (getMonth() == DatatypeConstants.FEBRUARY) {
              // years could not be set
              int maxDays = 29;
  
              if (eon == null) {
                  if(year!=DatatypeConstants.FIELD_UNDEFINED)
                      maxDays = maximumDayInMonthFor(year,getMonth());
              } else {
                  BigInteger years = getEonAndYear();
                  if (years != null) {
                      maxDays = maximumDayInMonthFor(getEonAndYear(), DatatypeConstants.FEBRUARY);
                  }
              }
              if (getDay() > maxDays) {
                  return false;
              }
          }
  
          // http://www.w3.org/2001/05/xmlschema-errata#e2-45
          if (getHour() == 24) {
              if(getMinute() != 0) {
                  return false;
              } else if (getSecond() != 0) {
                  return false;
              }
          }
  
          // XML Schema 1.0 specification defines year value of zero as
          // invalid. Allow this class to set year field to zero
          // since XML Schema 1.0 errata states that lexical zero will
          // be allowed in next version and treated as 1 B.C.E.
          if (eon == null) {
              // optimize check.
              if (year == 0) {
                  return false;
              }
          } else {
              BigInteger yearField = getEonAndYear();
              if (yearField != null) {
                  int result = compareField(yearField, BigInteger.ZERO);
                  if (result == DatatypeConstants.EQUAL) {
                      return false;
                  }
              }
          }
          return true;
      }
  
      /**
       * <p>Add <code>duration</code> to this instance.<\p>
       *
       * <p>The computation is specified in
       * <a href="http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes">XML Schema 1.0 Part 2, Appendix E,
       * <i>Adding durations to dateTimes</i>></a>.
       * <a href="#datetimefieldsmapping">date/time field mapping table</a>
       * defines the mapping from XML Schema 1.0 <code>dateTime</code> fields
       * to this class' representation of those fields.</p>
       *
       * @param duration Duration to add to this <code>XMLGregorianCalendar</code>.
       *
       * @throws NullPointerException  when <code>duration</code> parameter is <code>null</code>.
       */
      public void add(Duration duration) {
  
          /*
             * Extracted from
             * http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes
             * to ensure implemented properly. See spec for definitions of methods
             * used in algorithm.
             *
             * Given a dateTime S and a duration D, specifies how to compute a
             * dateTime E where E is the end of the time period with start S and
             * duration D i.e. E = S + D.
             *
             * The following is the precise specification.
             * These steps must be followed in the same order.
             * If a field in D is not specified, it is treated as if it were zero.
             * If a field in S is not specified, it is treated in the calculation
             * as if it were the minimum allowed value in that field, however,
             * after the calculation is concluded, the corresponding field in
             * E is removed (set to unspecified).
             *
             * Months (may be modified additionally below)
                 *  temp := S[month] + D[month]
                 *  E[month] := modulo(temp, 1, 13)
                 *  carry := fQuotient(temp, 1, 13)
             */
  
          boolean fieldUndefined[] = {
                  false,
                  false,
                  false,
                  false,
                  false,
                  false
          };
  
          int signum = duration.getSign();
  
          int startMonth = getMonth();
          if (startMonth == DatatypeConstants.FIELD_UNDEFINED) {
              startMonth = DatatypeConstants.JANUARY;
              fieldUndefined[MONTH] = true;
          }
  
          BigInteger dMonths = sanitize(duration.getField(DatatypeConstants.MONTHS), signum);
          BigInteger temp = BigInteger.valueOf((long) startMonth).add(dMonths);
          setMonth(temp.subtract(BigInteger.ONE).mod(TWELVE).intValue() + 1);
          BigInteger carry =
                  new BigDecimal(temp.subtract(BigInteger.ONE)).divide(new BigDecimal(TWELVE), BigDecimal.ROUND_FLOOR).toBigInteger();
  
          /* Years (may be modified additionally below)
              *  E[year] := S[year] + D[year] + carry
              */
          BigInteger startYear = getEonAndYear();
          if (startYear == null) {
              fieldUndefined[YEAR] = true;
              startYear = BigInteger.ZERO;
          }
          BigInteger dYears = sanitize(duration.getField(DatatypeConstants.YEARS), signum);
          BigInteger endYear = startYear.add(dYears).add(carry);
          setYear(endYear);
  
          /* Zone
                 *  E[zone] := S[zone]
             *
             * no-op since adding to this, not to a new end point.
             */
  
          /* Seconds
              *  temp := S[second] + D[second]
              *  E[second] := modulo(temp, 60)
              *  carry := fQuotient(temp, 60)
              */
          BigDecimal startSeconds;
          if (getSecond() == DatatypeConstants.FIELD_UNDEFINED) {
              fieldUndefined[SECOND] = true;
              startSeconds = DECIMAL_ZERO;
          } else {
              // seconds + fractionalSeconds
              startSeconds = getSeconds();
          }
  
          // Duration seconds is SECONDS + FRACTIONALSECONDS.
          BigDecimal dSeconds = DurationImpl.sanitize((BigDecimal) duration.getField(DatatypeConstants.SECONDS), signum);
          BigDecimal tempBD = startSeconds.add(dSeconds);
          BigDecimal fQuotient =
                  new BigDecimal(new BigDecimal(tempBD.toBigInteger()).divide(DECIMAL_SIXTY, BigDecimal.ROUND_FLOOR).toBigInteger());
          BigDecimal endSeconds = tempBD.subtract(fQuotient.multiply(DECIMAL_SIXTY));
  
          carry = fQuotient.toBigInteger();
          setSecond(endSeconds.intValue());
          BigDecimal tempFracSeconds = endSeconds.subtract(new BigDecimal(BigInteger.valueOf((long) getSecond())));
          if (tempFracSeconds.compareTo(DECIMAL_ZERO) < 0) {
              setFractionalSecond(DECIMAL_ONE.add(tempFracSeconds));
              if (getSecond() == 0) {
                  setSecond(59);
                  carry = carry.subtract(BigInteger.ONE);
              } else {
                  setSecond(getSecond() - 1);
              }
          } else {
              setFractionalSecond(tempFracSeconds);
          }
  
          /* Minutes
                 *  temp := S[minute] + D[minute] + carry
                 *  E[minute] := modulo(temp, 60)
                 *  carry := fQuotient(temp, 60)
             */
          int startMinutes = getMinute();
          if (startMinutes == DatatypeConstants.FIELD_UNDEFINED) {
              fieldUndefined[MINUTE] = true;
              startMinutes = 0;
          }
          BigInteger dMinutes = sanitize(duration.getField(DatatypeConstants.MINUTES), signum);
  
          temp = BigInteger.valueOf(startMinutes).add(dMinutes).add(carry);
          setMinute(temp.mod(SIXTY).intValue());
          carry = new BigDecimal(temp).divide(DECIMAL_SIXTY, BigDecimal.ROUND_FLOOR).toBigInteger();
  
          /* Hours
                 *  temp := S[hour] + D[hour] + carry
                 *  E[hour] := modulo(temp, 24)
                 *  carry := fQuotient(temp, 24)
             */
          int startHours = getHour();
          if (startHours == DatatypeConstants.FIELD_UNDEFINED) {
              fieldUndefined[HOUR] = true;
              startHours = 0;
          }
          BigInteger dHours = sanitize(duration.getField(DatatypeConstants.HOURS), signum);
  
          temp = BigInteger.valueOf(startHours).add(dHours).add(carry);
          setHour(temp.mod(TWENTY_FOUR).intValue(), false);
          carry = new BigDecimal(temp).divide(new BigDecimal(TWENTY_FOUR), BigDecimal.ROUND_FLOOR).toBigInteger();
  
          /* Days
             *  if S[day] > maximumDayInMonthFor(E[year], E[month])
             *       + tempDays := maximumDayInMonthFor(E[year], E[month])
             *  else if S[day] < 1
             *       + tempDays := 1
             *  else
             *       + tempDays := S[day]
             *  E[day] := tempDays + D[day] + carry
             *  START LOOP
             *       + IF E[day] < 1
             *             # E[day] := E[day] +
              *                 maximumDayInMonthFor(E[year], E[month] - 1)
             *             # carry := -1
             *       + ELSE IF E[day] > maximumDayInMonthFor(E[year], E[month])
             *             # E[day] :=
              *                    E[day] - maximumDayInMonthFor(E[year], E[month])
             *             # carry := 1
             *       + ELSE EXIT LOOP
             *       + temp := E[month] + carry
             *       + E[month] := modulo(temp, 1, 13)
             *       + E[year] := E[year] + fQuotient(temp, 1, 13)
             *       + GOTO START LOOP
             */
          BigInteger tempDays;
          int startDay = getDay();
          if (startDay == DatatypeConstants.FIELD_UNDEFINED) {
              fieldUndefined[DAY] = true;
              startDay = 1;
          }
          BigInteger dDays = sanitize(duration.getField(DatatypeConstants.DAYS), signum);
          int maxDayInMonth = maximumDayInMonthFor(getEonAndYear(), getMonth());
          if (startDay > maxDayInMonth) {
              tempDays = BigInteger.valueOf(maxDayInMonth);
          } else if (startDay < 1) {
              tempDays = BigInteger.ONE;
          } else {
              tempDays = BigInteger.valueOf(startDay);
          }
          BigInteger endDays = tempDays.add(dDays).add(carry);
          int monthCarry;
          int intTemp;
          while (true) {
              if (endDays.compareTo(BigInteger.ONE) < 0) {
                  // calculate days in previous month, watch for month roll over
                  BigInteger mdimf = null;
                  if (month >= 2) {
                      mdimf = BigInteger.valueOf(maximumDayInMonthFor(getEonAndYear(), getMonth() - 1));
                  } else {
                      // roll over to December of previous year
                      mdimf = BigInteger.valueOf(maximumDayInMonthFor(getEonAndYear().subtract(BigInteger.valueOf((long) 1)), 12));
                  }
                  endDays = endDays.add(mdimf);
                  monthCarry = -1;
              } else if (endDays.compareTo(BigInteger.valueOf(maximumDayInMonthFor(getEonAndYear(), getMonth()))) > 0) {
                  endDays = endDays.add(BigInteger.valueOf(-maximumDayInMonthFor(getEonAndYear(), getMonth())));
                  monthCarry = 1;
              } else {
                  break;
              }
  
              intTemp = getMonth() + monthCarry;
              int endMonth = (intTemp - 1) % (13 - 1);
              int quotient;
              if (endMonth < 0) {
                  endMonth = (13 - 1) + endMonth + 1;
                  quotient = new BigDecimal(intTemp - 1).divide(new BigDecimal(TWELVE), BigDecimal.ROUND_UP).intValue();
              } else {
                  quotient = (intTemp - 1) / (13 - 1);
                  endMonth += 1;
              }
              setMonth(endMonth);
              if (quotient != 0) {
                  setYear(getEonAndYear().add(BigInteger.valueOf(quotient)));
              }
          }
          setDay(endDays.intValue());
  
          // set fields that where undefined before this addition, back to undefined.
          for (int i = YEAR; i <= SECOND; i++) {
              if (fieldUndefined[i]) {
                  switch (i) {
                  case YEAR:
                      setYear(DatatypeConstants.FIELD_UNDEFINED);
                      break;
                  case MONTH:
                      setMonth(DatatypeConstants.FIELD_UNDEFINED);
                      break;
                  case DAY:
                      setDay(DatatypeConstants.FIELD_UNDEFINED);
                      break;
                  case HOUR:
                      setHour(DatatypeConstants.FIELD_UNDEFINED, false);
                      break;
                  case MINUTE:
                      setMinute(DatatypeConstants.FIELD_UNDEFINED);
                      break;
                  case SECOND:
                      setSecond(DatatypeConstants.FIELD_UNDEFINED);
                      setFractionalSecond(null);
                      break;
                  }
              }
          }
      }
  
      private static final BigInteger FOUR = BigInteger.valueOf(4);
      private static final BigInteger HUNDRED = BigInteger.valueOf(100);
      private static final BigInteger FOUR_HUNDRED = BigInteger.valueOf(400);
      private static final BigInteger SIXTY = BigInteger.valueOf(60);
      private static final BigInteger TWENTY_FOUR = BigInteger.valueOf(24);
      private static final BigInteger TWELVE = BigInteger.valueOf(12);
      private static final BigDecimal DECIMAL_ZERO = new BigDecimal("0");
      private static final BigDecimal DECIMAL_ONE = new BigDecimal("1");
      private static final BigDecimal DECIMAL_SIXTY = new BigDecimal("60");
  
  
      private static int daysInMonth[] = { 0,  // XML Schema months start at 1.
                                         31, 28, 31, 30, 31, 30,
                                         31, 31, 30, 31, 30, 31};
  
      private static int maximumDayInMonthFor(BigInteger year, int month) {
          if (month != DatatypeConstants.FEBRUARY) {
              return daysInMonth[month];
          } else {
              if (year.mod(FOUR_HUNDRED).equals(BigInteger.ZERO) ||
                      (!year.mod(HUNDRED).equals(BigInteger.ZERO) &&
                              year.mod(FOUR).equals(BigInteger.ZERO))) {
                  // is a leap year.
                  return 29;
              } else {
                  return daysInMonth[month];
              }
          }
      }
  
      private static int maximumDayInMonthFor(int year, int month) {
          if (month != DatatypeConstants.FEBRUARY) {
              return daysInMonth[month];
          } else {
              if (((year % 400) == 0) ||
                      (((year % 100) != 0) && ((year % 4) == 0))) {
                  // is a leap year.
                  return 29;
              } else {
                  return daysInMonth[DatatypeConstants.FEBRUARY];
              }
          }
      }
  
      /**
       * <p>Convert <code>this</code> to <code>java.util.GregorianCalendar</code>.</p>
       *
       * <p>When <code>this</code> instance has an undefined field, this
       * conversion relies on the <code>java.util.GregorianCalendar</code> default
       * for its corresponding field. A notable difference between
       * XML Schema 1.0 date/time datatypes and <code>java.util.GregorianCalendar</code>
       * is that Timezone value is optional for date/time datatypes and it is
       * a required field for <code>java.util.GregorianCalendar</code>. See javadoc
       * for <code>java.util.TimeZone.getDefault()</code> on how the default
       * is determined. To explicitly specify the <code>TimeZone</code>
       * instance, see
       * {@link #toGregorianCalendar(TimeZone, Locale, XMLGregorianCalendar)}.</p>
       *
       * <table border="2" rules="all" cellpadding="2">
       *   <thead>
       *     <tr>
       *       <th align="center" colspan="2">
       *          Field by Field Conversion from this class to
       *          <code>java.util.GregorianCalendar</code>
       *       </th>
       *     </tr>
       *   </thead>
       *   <tbody>
       *     <tr>
       *        <th><code>java.util.GregorianCalendar</code> field</th>
       *        <th><code>javax.xml.datatype.XMLGregorianCalendar</code> field</th>
       *     </tr>
       *     <tr>
       *       <th><code>ERA</code></th>
       *       <th>{@link #getEonAndYear()}<code>.signum() < 0 ? GregorianCalendar.BC : GregorianCalendar.AD</code></th>
       *     </tr>
       *     <tr>
       *       <th><code>YEAR</code></th>
       *       <th>{@link #getEonAndYear()}<code>.abs().intValue()</code><i>*</i></th>
       *     </tr>
       *     <tr>
       *       <th><code>MONTH</code></th>
       *       <th>{@link #getMonth()}<code> - 1</code></th>
       *     </tr>
       *     <tr>
       *       <th><code>DAY_OF_MONTH</code></th>
       *       <th>{@link #getDay()}</th>
       *     </tr>
       *     <tr>
       *       <th><code>AM_PM</code></th>
       *       <th>{@link #getHour()} < 12 : Calendar.AM : Calendar.PM</th>
       *     </tr>
       *     <tr>
       *       <th><code>HOUR_OF_DAY</code></th>
       *       <th>{@link #getHour()}</th>
       *     </tr>
       *     <tr>
       *       <th><code>MINUTE</code></th>
       *       <th>{@link #getMinute()}</th>
       *     </tr>
       *     <tr>
       *       <th><code>SECOND</code></th>
       *       <th>{@link #getSecond()}</th>
       *     </tr>
       *     <tr>
       *       <th><code>MILLISECOND</code></th>
       *       <th>get millisecond order from {@link #getFractionalSecond()}<i>*</i> </th>
       *     </tr>
       *     <tr>
       *       <th><code>GregorianCalendar.setTimeZone(TimeZone)</code></th>
       *       <th>{@link #getTimezone()} formatted into Custom timezone id</th>
       *     </tr>
       *   </tbody>
       * </table>
       * <i>*</i> designates possible loss of precision during the conversion due
       * to source datatype having higer precison than target datatype.
       *
       * <p>To ensure consistency in conversion implementations, the new
       * <code>GregorianCalendar</code> should be instantiated in following
       * manner.
       * <ul>
       *   <li>Using <code>timeZone</code> value as defined above, create a new
       * <code>java.util.GregorianCalendar(timeZone,Locale.getDefault())</code>.
       *   </li>
       *   <li>Initialize all GregorianCalendar fields by calling {(@link GegorianCalendar#clear()}.</li>
       *   <li>Obtain a pure Gregorian Calendar by invoking
       *   <code>GregorianCalendar.setGregorianChange(
       *   new Date(Long.MIN_VALUE))</code>.</li>
       *   <li>Its fields ERA, YEAR, MONTH, DAY_OF_MONTH, HOUR_OF_DAY,
       *       MINUTE, SECOND and MILLISECOND are set using the method
       *       <code>Calendar.set(int,int)</code></li>
       * </ul>
       * </p>
       *
       * @see #toGregorianCalendar(java.util.TimeZone, java.util.Locale, XMLGregorianCalendar)
       */
      public java.util.GregorianCalendar toGregorianCalendar() {
  
          GregorianCalendar result = null;
          final int DEFAULT_TIMEZONE_OFFSET = DatatypeConstants.FIELD_UNDEFINED;
          TimeZone tz = getTimeZone(DEFAULT_TIMEZONE_OFFSET);
          /** Use the following instead for JDK7 only:
           * Locale locale = Locale.getDefault(Locale.Category.FORMAT);
           */
          Locale locale = getDefaultLocale();
  
          result = new GregorianCalendar(tz, locale);
          result.clear();
          result.setGregorianChange(PURE_GREGORIAN_CHANGE);
  
          // if year( and eon) are undefined, leave default Calendar values
          BigInteger year = getEonAndYear();
          if (year != null) {
              result.set(Calendar.ERA, year.signum() == -1 ? GregorianCalendar.BC : GregorianCalendar.AD);
              result.set(Calendar.YEAR, year.abs().intValue());
          }
  
          // only set month if it is set
          if (month != DatatypeConstants.FIELD_UNDEFINED) {
              // Calendar.MONTH is zero based while XMLGregorianCalendar month field is not.
              result.set(Calendar.MONTH, month - 1);
          }
  
          // only set day if it is set
          if (day != DatatypeConstants.FIELD_UNDEFINED) {
              result.set(Calendar.DAY_OF_MONTH, day);
          }
  
          // only set hour if it is set
          if (hour != DatatypeConstants.FIELD_UNDEFINED) {
              result.set(Calendar.HOUR_OF_DAY, hour);
          }
  
          // only set minute if it is set
          if (minute != DatatypeConstants.FIELD_UNDEFINED) {
              result.set(Calendar.MINUTE, minute);
          }
  
          // only set second if it is set
          if (second != DatatypeConstants.FIELD_UNDEFINED) {
              result.set(Calendar.SECOND, second);
          }
  
          // only set millisend if it is set
          if (fractionalSecond != null) {
              result.set(Calendar.MILLISECOND, getMillisecond());
          }
  
          return result;
      }
  
      /**
       *
       * @return default locale
       */
      private Locale getDefaultLocale() {
  
          String lang = SecuritySupport.getSystemProperty("user.language.format");
          String country = SecuritySupport.getSystemProperty("user.country.format");
          String variant = SecuritySupport.getSystemProperty("user.variant.format");
          Locale locale = null;
          if (lang != null) {
              if (country != null) {
                  if (variant != null) {
                      locale = new Locale(lang, country, variant);
                  } else {
                      locale = new Locale(lang, country);
                  }
              } else {
                  locale = new Locale(lang);
              }
          }
          if (locale == null) {
              locale = Locale.getDefault();
          }
          return locale;
      }
  
      /**
       * <p>Convert <code>this</code> along with provided parameters
       * to <code>java.util.GregorianCalendar</code> instance.</p>
       *
       * <p> Since XML Schema 1.0 date/time datetypes has no concept of
       * timezone ids or daylight savings timezone ids, this conversion operation
       * allows the user to explicitly specify one with
       * <code>timezone</code> parameter.</p>
       *
       * <p>To compute the return value's <code>TimeZone</code> field,
       * <ul>
       * <li>when parameter <code>timeZone</code> is non-null,
       * it is the timezone field.</li>
       * <li>else when <code>this.getTimezone() != DatatypeConstants.FIELD_UNDEFINED</code>,
       * create a <code>java.util.TimeZone</code> with a custom timezone id
       * using the <code>this.getTimezone()</code>.</li>
       * <li>else when <code>defaults.getTimezone() != DatatypeConstants.FIELD_UNDEFINED</code>,
       * create a <code>java.util.TimeZone</code> with a custom timezone id
       * using <code>defaults.getTimezone()</code>.</li>
       * <li>else use the <code>GregorianCalendar</code> default timezone value
       * for the host is definedas specified by
       * <code>java.util.TimeZone.getDefault()</code>.</li></p>
       *
       * <p>To ensure consistency in conversion implementations, the new
       * <code>GregorianCalendar</code> should be instantiated in following
       * manner.
       * <ul>
       *   <li>Create a new <code>java.util.GregorianCalendar(TimeZone,
       *       Locale)</code> with TimeZone set as specified above and the
       *       <code>Locale</code> parameter.
       *   </li>
       *   <li>Initialize all GregorianCalendar fields by calling {(@link GegorianCalendar#clear()}.</li>
       *   <li>Obtain a pure Gregorian Calendar by invoking
       *   <code>GregorianCalendar.setGregorianChange(
       *   new Date(Long.MIN_VALUE))</code>.</li>
       *   <li>Its fields ERA, YEAR, MONTH, DAY_OF_MONTH, HOUR_OF_DAY,
       *       MINUTE, SECOND and MILLISECOND are set using the method
       *       <code>Calendar.set(int,int)</code></li>
       * </ul>
       *
       * @param timezone provide Timezone. <code>null</code> is a legal value.
       * @param aLocale  provide explicit Locale. Use default GregorianCalendar locale if
       *                 value is <code>null</code>.
       * @param defaults provide default field values to use when corresponding
       *                 field for this instance is DatatypeConstants.FIELD_UNDEFINED or null.
       *                 If <code>defaults</code>is <code>null</code> or a field
       *                 within the specified <code>defaults</code> is undefined,
       *                 just use <code>java.util.GregorianCalendar</code> defaults.
       * @return a java.util.GregorianCalendar conversion of this instance.
       *
       * @see #LEAP_YEAR_DEFAULT
       */
      public GregorianCalendar toGregorianCalendar(TimeZone timezone,
                                                   Locale aLocale,
                                                   XMLGregorianCalendar defaults) {
          GregorianCalendar result = null;
          TimeZone tz = timezone;
          if (tz == null) {
              int defaultZoneoffset = DatatypeConstants.FIELD_UNDEFINED;
              if (defaults != null) {
                  defaultZoneoffset = defaults.getTimezone();
              }
              tz = getTimeZone(defaultZoneoffset);
          }
          if (aLocale == null) {
              aLocale = Locale.getDefault();
          }
          result = new GregorianCalendar(tz, aLocale);
          result.clear();
          result.setGregorianChange(PURE_GREGORIAN_CHANGE);
  
          // if year( and eon) are undefined, leave default Calendar values
          BigInteger year = getEonAndYear();
          if (year != null) {
              result.set(Calendar.ERA, year.signum() == -1 ? GregorianCalendar.BC : GregorianCalendar.AD);
              result.set(Calendar.YEAR, year.abs().intValue());
          } else {
              // use default if set
              BigInteger defaultYear = (defaults != null) ? defaults.getEonAndYear() : null;
              if (defaultYear != null) {
                  result.set(Calendar.ERA, defaultYear.signum() == -1 ? GregorianCalendar.BC : GregorianCalendar.AD);
                  result.set(Calendar.YEAR, defaultYear.abs().intValue());
              }
          }
  
          // only set month if it is set
          if (month != DatatypeConstants.FIELD_UNDEFINED) {
              // Calendar.MONTH is zero based while XMLGregorianCalendar month field is not.
              result.set(Calendar.MONTH, month - 1);
          } else {
              // use default if set
              int defaultMonth = (defaults != null) ? defaults.getMonth() : DatatypeConstants.FIELD_UNDEFINED;
              if (defaultMonth != DatatypeConstants.FIELD_UNDEFINED) {
                  // Calendar.MONTH is zero based while XMLGregorianCalendar month field is not.
                  result.set(Calendar.MONTH, defaultMonth - 1);
              }
          }
  
          // only set day if it is set
          if (day != DatatypeConstants.FIELD_UNDEFINED) {
              result.set(Calendar.DAY_OF_MONTH, day);
          } else {
              // use default if set
              int defaultDay = (defaults != null) ? defaults.getDay() : DatatypeConstants.FIELD_UNDEFINED;
              if (defaultDay != DatatypeConstants.FIELD_UNDEFINED) {
                  result.set(Calendar.DAY_OF_MONTH, defaultDay);
              }
          }
  
          // only set hour if it is set
          if (hour != DatatypeConstants.FIELD_UNDEFINED) {
              result.set(Calendar.HOUR_OF_DAY, hour);
          } else {
              // use default if set
              int defaultHour = (defaults != null) ? defaults.getHour() : DatatypeConstants.FIELD_UNDEFINED;
              if (defaultHour != DatatypeConstants.FIELD_UNDEFINED) {
                  result.set(Calendar.HOUR_OF_DAY, defaultHour);
              }
          }
  
          // only set minute if it is set
          if (minute != DatatypeConstants.FIELD_UNDEFINED) {
              result.set(Calendar.MINUTE, minute);
          } else {
              // use default if set
              int defaultMinute = (defaults != null) ? defaults.getMinute() : DatatypeConstants.FIELD_UNDEFINED;
              if (defaultMinute != DatatypeConstants.FIELD_UNDEFINED) {
                  result.set(Calendar.MINUTE, defaultMinute);
              }
          }
  
          // only set second if it is set
          if (second != DatatypeConstants.FIELD_UNDEFINED) {
              result.set(Calendar.SECOND, second);
          } else {
              // use default if set
              int defaultSecond = (defaults != null) ? defaults.getSecond() : DatatypeConstants.FIELD_UNDEFINED;
              if (defaultSecond != DatatypeConstants.FIELD_UNDEFINED) {
                  result.set(Calendar.SECOND, defaultSecond);
              }
          }
  
          // only set millisend if it is set
          if (fractionalSecond != null) {
              result.set(Calendar.MILLISECOND, getMillisecond());
          } else {
              // use default if set
              BigDecimal defaultFractionalSecond = (defaults != null) ? defaults.getFractionalSecond() : null;
              if (defaultFractionalSecond != null) {
                  result.set(Calendar.MILLISECOND, defaults.getMillisecond());
              }
          }
  
          return result;
      }
  
      /**
       * <p>Returns a <code>java.util.TimeZone</code> for this class.</p>
       *
       * <p>If timezone field is defined for this instance,
       * returns TimeZone initialized with custom timezone id
       * of zoneoffset. If timezone field is undefined,
       * try the defaultZoneoffset that was passed in.
       * If defaultZoneoffset is DatatypeConstants.FIELD_UNDEFINED, return
       * default timezone for this host.
       * (Same default as java.util.GregorianCalendar).</p>
       *
       * @param defaultZoneoffset default zoneoffset if this zoneoffset is
       * {@link DatatypeConstants#FIELD_UNDEFINED}.
       *
       * @return TimeZone for this.
       */
      public TimeZone getTimeZone(int defaultZoneoffset) {
          TimeZone result = null;
          int zoneoffset = getTimezone();
  
          if (zoneoffset == DatatypeConstants.FIELD_UNDEFINED) {
              zoneoffset = defaultZoneoffset;
          }
          if (zoneoffset == DatatypeConstants.FIELD_UNDEFINED) {
              result = TimeZone.getDefault();
          } else {
              // zoneoffset is in minutes. Convert to custom timezone id format.
              char sign = zoneoffset < 0 ? '-' : '+';
              if (sign == '-') {
                  zoneoffset = -zoneoffset;
              }
              int hour = zoneoffset / 60;
              int minutes = zoneoffset - (hour * 60);
  
              // Javadoc for java.util.TimeZone documents max length
              // for customTimezoneId is 8 when optional ':' is not used.
              // Format is
              // "GMT" ('-'|''+') (digit digit?) (digit digit)?
              //                   hour          minutes
              StringBuffer customTimezoneId = new StringBuffer(8);
              customTimezoneId.append("GMT");
              customTimezoneId.append(sign);
              customTimezoneId.append(hour);
              if (minutes != 0) {
                  customTimezoneId.append(minutes);
              }
              result = TimeZone.getTimeZone(customTimezoneId.toString());
          }
          return result;
      }
  
      /**
       * <p>Creates and returns a copy of this object.</p>
       *
       * @return copy of this <code>Object</code>
       */
     public Object clone() {
          // Both this.eon and this.fractionalSecond are instances
          // of immutable classes, so they do not need to be cloned.
         return new XMLGregorianCalendarImpl(getEonAndYear(),
                          this.month, this.day,
                          this.hour, this.minute, this.second,
                          this.fractionalSecond,
                          this.timezone);
      }
  
      /**
       * <p>Unset all fields to undefined.</p>
       *
       * <p>Set all int fields to {@link DatatypeConstants#FIELD_UNDEFINED} and reference fields
       * to null.</p>
       */
      public void clear() {
          eon = null;
          year = DatatypeConstants.FIELD_UNDEFINED;
          month = DatatypeConstants.FIELD_UNDEFINED;
          day = DatatypeConstants.FIELD_UNDEFINED;
          timezone = DatatypeConstants.FIELD_UNDEFINED;  // in minutes
          hour = DatatypeConstants.FIELD_UNDEFINED;
          minute = DatatypeConstants.FIELD_UNDEFINED;
          second = DatatypeConstants.FIELD_UNDEFINED;
          fractionalSecond = null;
      }
  
      public void setMillisecond(int millisecond) {
          if (millisecond == DatatypeConstants.FIELD_UNDEFINED) {
              fractionalSecond = null;
          } else {
              if(millisecond<0 || 999<millisecond)
                  if(millisecond!=DatatypeConstants.FIELD_UNDEFINED)
                      invalidFieldValue(MILLISECOND, millisecond);
              fractionalSecond = new BigDecimal((long) millisecond).movePointLeft(3);
          }
      }
  
      public void setFractionalSecond(BigDecimal fractional) {
          if (fractional != null) {
              if ((fractional.compareTo(DECIMAL_ZERO) < 0) ||
                      (fractional.compareTo(DECIMAL_ONE) > 0)) {
                  throw new IllegalArgumentException(DatatypeMessageFormatter.formatMessage(null,
                          "InvalidFractional", new Object[]{fractional}));
              }
          }
          this.fractionalSecond = fractional;
      }
  
      private final class Parser {
          private final String format;
          private final String value;
  
          private final int flen;
          private final int vlen;
  
          private int fidx;
          private int vidx;
  
          private Parser(String format, String value) {
              this.format = format;
              this.value = value;
              this.flen = format.length();
              this.vlen = value.length();
          }
  
          /**
           * <p>Parse a formated <code>String</code> into an <code>XMLGregorianCalendar</code>.</p>
           *
           * <p>If <code>String</code> is not formated as a legal <code>XMLGregorianCalendar</code> value,
           * an <code>IllegalArgumentException</code> is thrown.</p>
           *
           * @throws IllegalArgumentException If <code>String</code> is not formated as a legal <code>XMLGregorianCalendar</code> value.
           */
          public void parse() throws IllegalArgumentException {
              while (fidx < flen) {
                  char fch = format.charAt(fidx++);
  
                  if (fch != '%') { // not a meta character
                      skip(fch);
                      continue;
                  }
  
                  // seen meta character. we don't do error check against the format
                  switch (format.charAt(fidx++)) {
                      case 'Y' : // year
                          parseAndSetYear(4);
                          break;
  
                      case 'M' : // month
                          setMonth(parseInt(2, 2));
                          break;
  
                      case 'D' : // days
                          setDay(parseInt(2, 2));
                          break;
  
                      case 'h' : // hours
                          setHour(parseInt(2, 2), false);
                          break;
  
                      case 'm' : // minutes
                          setMinute(parseInt(2, 2));
                          break;
  
                      case 's' : // parse seconds.
                          setSecond(parseInt(2, 2));
  
                          if (peek() == '.') {
                              setFractionalSecond(parseBigDecimal());
                          }
                          break;
  
                      case 'z' : // time zone. missing, 'Z', or [+-]nn:nn
                          char vch = peek();
                          if (vch == 'Z') {
                              vidx++;
                              setTimezone(0);
                          } else if (vch == '+' || vch == '-') {
                              vidx++;
                              int h = parseInt(2, 2);
                              skip(':');
                              int m = parseInt(2, 2);
                              setTimezone((h * 60 + m) * (vch == '+' ? 1 : -1));
                          }
  
                          break;
  
                      default :
                          // illegal meta character. impossible.
                          throw new InternalError();
                  }
              }
  
              if (vidx != vlen) {
                  // some tokens are left in the input
                  throw new IllegalArgumentException(value); //,vidx);
              }
              testHour();
          }
  
          private char peek() throws IllegalArgumentException {
              if (vidx == vlen) {
                  return (char) -1;
              }
              return value.charAt(vidx);
          }
  
          private char read() throws IllegalArgumentException {
              if (vidx == vlen) {
                  throw new IllegalArgumentException(value); //,vidx);
              }
              return value.charAt(vidx++);
          }
  
          private void skip(char ch) throws IllegalArgumentException {
              if (read() != ch) {
                  throw new IllegalArgumentException(value); //,vidx-1);
              }
          }
  
          private int parseInt(int minDigits, int maxDigits)
              throws IllegalArgumentException {
  
              int n = 0;
              char ch;
              int vstart = vidx;
              while (isDigit(ch=peek()) && (vidx - vstart) <= maxDigits) {
                  vidx++;
                  n = n*10 + ch-'0';
              }
              if ((vidx - vstart) < minDigits) {
                  // we are expecting more digits
                  throw new IllegalArgumentException(value); //,vidx);
              }
  
              return n;
          }
  
          private void parseAndSetYear(int minDigits)
                  throws IllegalArgumentException {
              int vstart = vidx;
              int n = 0;
              boolean neg = false;
  
              // skip leading negative, if it exists
              if (peek() == '-') {
                  vidx++;
                  neg = true;
              }
              while(true) {
                  char ch = peek();
                  if(!isDigit(ch))
                      break;
                  vidx++;
                  n = n*10 + ch-'0';
              }
  
              if ((vidx - vstart) < minDigits) {
                  // we are expecting more digits
                  throw new IllegalArgumentException(value); //,vidx);
              }
  
              if(vidx-vstart<7) {
                  // definitely int only. I don't know the exact # of digits that can be in int,
                  // but as long as we can catch (0-9999) range, that should be enough.
                  if(neg)     n = -n;
                  year = n;
                  eon = null;
              } else {
                  setYear(new BigInteger(value.substring(vstart, vidx)));
              }
          }
  
          private BigDecimal parseBigDecimal()
                  throws IllegalArgumentException {
              int vstart = vidx;
  
              if (peek() == '.') {
                  vidx++;
              } else {
                  throw new IllegalArgumentException(value);
              }
              while (isDigit(peek())) {
                  vidx++;
              }
              return new BigDecimal(value.substring(vstart, vidx));
          }
      }
  
      private static boolean isDigit(char ch) {
          return '0' <= ch && ch <= '9';
      }
  
      /**
       * Prints this object according to the format specification.
       *
       * <p>
       * I wrote a custom format method for a particular format string to
       * see if it improves the performance, but it didn't. So this interpreting
       * approach isn't too bad.
       *
       * <p>
       * StringBuffer -> StringBuilder change had a very visible impact.
       * It almost cut the execution time to half, but unfortunately we can't use it
       * because we need to run on JDK 1.3
       */
      private String format( String format ) {
          char[] buf = new char[32];
          int bufPtr = 0;
  
          int fidx=0,flen=format.length();
  
          while(fidx<flen) {
              char fch = format.charAt(fidx++);
              if(fch!='%') {// not a meta char
                  buf[bufPtr++] = fch;
                  continue;
              }
  
              switch(format.charAt(fidx++)) {
              case 'Y':
                  if(eon==null) {
                      // optimized path
                      int y = getYear();
                      if(y<0) {
                          buf[bufPtr++] = '-';
                          y = -y;
                      }
                      bufPtr = print4Number(buf,bufPtr,y);
                  } else {
                      String s = getEonAndYear().toString();
                      // reallocate the buffer now so that it has enough space
                      char[] n = new char[buf.length+s.length()];
                      System.arraycopy(buf,0,n,0,bufPtr);
                      buf = n;
                      for(int i=s.length();i<4;i++)
                          buf[bufPtr++] = '0';
                      s.getChars(0,s.length(),buf,bufPtr);
                      bufPtr += s.length();
                  }
                  break;
              case 'M':
                  bufPtr = print2Number(buf,bufPtr,getMonth());
                  break;
              case 'D':
                  bufPtr = print2Number(buf,bufPtr,getDay());
                  break;
              case 'h':
                  bufPtr = print2Number(buf,bufPtr,getHour());
                  break;
              case 'm':
                  bufPtr = print2Number(buf,bufPtr,getMinute());
                  break;
              case 's':
                  bufPtr = print2Number(buf,bufPtr,getSecond());
                  if (getFractionalSecond() != null) {
                      // Note: toPlainString() isn't available before Java 1.5
                      String frac = getFractionalSecond().toString();
  
                      int pos = frac.indexOf("E-");
                      if (pos >= 0) {
                          String zeros = frac.substring(pos+2);
                          frac = frac.substring(0,pos);
                          pos = frac.indexOf(".");
                          if (pos >= 0) {
                              frac = frac.substring(0,pos) + frac.substring(pos+1);
                          }
                          int count = Integer.parseInt(zeros);
                          if (count < 40) {
                              frac = "00000000000000000000000000000000000000000".substring(0,count-1) + frac;
                          } else {
                              // do it the hard way
                              while (count > 1) {
                                  frac = "0" + frac;
                                  count--;
                              }
                          }
                          frac = "0." + frac;
                      }
  
                      // reallocate the buffer now so that it has enough space
                      char[] n = new char[buf.length+frac.length()];
                      System.arraycopy(buf,0,n,0,bufPtr);
                      buf = n;
                      //skip leading zero.
                      frac.getChars(1, frac.length(), buf, bufPtr);
                      bufPtr += frac.length()-1;
                  }
                  break;
              case 'z':
                  int offset = getTimezone();
                  if (offset == 0) {
                      buf[bufPtr++] = 'Z';
                  } else
                  if (offset != DatatypeConstants.FIELD_UNDEFINED) {
                      if (offset < 0) {
                          buf[bufPtr++] = '-';
                          offset *= -1;
                      } else {
                          buf[bufPtr++] = '+';
                      }
                      bufPtr = print2Number(buf, bufPtr, offset / 60);
                      buf[bufPtr++] = ':';
                      bufPtr = print2Number(buf, bufPtr, offset % 60);
                  }
                  break;
              default:
                  throw new InternalError();  // impossible
              }
          }
  
          return new String(buf,0,bufPtr);
      }
  
      /**
       * Prints an int as two digits into the buffer.
       *
       * @param number
       *      Number to be printed. Must be positive.
       */
      private int print2Number( char[] out, int bufptr, int number ) {
          out[bufptr++] = (char) ('0'+(number/10));
          out[bufptr++] = (char) ('0'+(number%10));
          return bufptr;
      }
  
      /**
       * Prints an int as four digits into the buffer.
       *
       * @param number
       *      Number to be printed. Must be positive.
       */
      private int print4Number( char[] out, int bufptr, int number ) {
          out[bufptr+3] = (char) ('0'+(number%10));
          number /= 10;
          out[bufptr+2] = (char) ('0'+(number%10));
          number /= 10;
          out[bufptr+1] = (char) ('0'+(number%10));
          number /= 10;
          out[bufptr  ] = (char) ('0'+(number%10));
          return bufptr+4;
      }
  
      /**
       * Compute <code>value*signum</code> where value==null is treated as
       * value==0.
       * @return non-null {@link BigInteger}.
       */
      static BigInteger sanitize(Number value, int signum) {
          if (signum == 0 || value == null) {
              return BigInteger.ZERO;
          }
          return (signum <  0)? ((BigInteger)value).negate() : (BigInteger)value;
      }
  
      /** <p><code>reset()</code> is designed to allow the reuse of existing
       * <code>XMLGregorianCalendar</code>s thus saving resources associated
       *  with the creation of new <code>XMLGregorianCalendar</code>s.</p>
       */
      public void reset() {
          //PENDING : Implementation of reset method
      }
  }
  