content: /*
   * Copyright 2002-2019 Drew Noakes and contributors
   *
   *    Licensed under the Apache License, Version 2.0 (the "License");
   *    you may not use this file except in compliance with the License.
   *    You may obtain a copy of the License at
   *
   *        https://www.apache.org/licenses/LICENSE-2.0
   *
   *    Unless required by applicable law or agreed to in writing, software
   *    distributed under the License is distributed on an "AS IS" BASIS,
   *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *    See the License for the specific language governing permissions and
   *    limitations under the License.
   *
   * More information about this project is available at:
   *
   *    https://drewnoakes.com/code/exif/
   *    https://github.com/drewnoakes/metadata-extractor
   */
  package com.drew.lang;
  
  import java.util.Date;
  
  /**
   * @author Drew Noakes https://drewnoakes.com
   */
  public class DateUtil
  {
      private static int[] _daysInMonth365 = new int[] {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  
      /**
       * The offset (in milliseconds) to add to a MP4 date/time integer value to
       * align with Java's Epoch.
       */
      private static final long EPOCH_1_JAN_1904 = -2082844800000L;
  
      public static boolean isValidDate(int year, int month, int day)
      {
          if (year < 1 || year > 9999 || month < 0 || month > 11)
              return false;
  
          int daysInMonth = _daysInMonth365[month];
          if (month == 1)
          {
              boolean isLeapYear = year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
              if (isLeapYear)
                  daysInMonth++;
          }
  
          return day >= 1 && day <= daysInMonth;
      }
  
      public static boolean isValidTime(int hours, int minutes, int seconds)
      {
          return hours >= 0 && hours < 24
              && minutes >= 0 && minutes < 60
              && seconds >= 0 && seconds < 60;
      }
  
      public static Date get1Jan1904EpochDate(long seconds)
      {
          return new Date((seconds * 1000) + EPOCH_1_JAN_1904);
      }
  }
  