**Use case**

Workload generation with continuous queries.

**Describe the solution you'd like**

Similar to now() but non-constant.

void registerFunctionToStartOfMonth(FunctionFactory &);
void registerFunctionToLastDayOfMonth(FunctionFactory &);
void registerFunctionToStartOfQuarter(FunctionFactory &);
void registerFunctionToStartOfYear(FunctionFactory &);
void registerFunctionToStartOfMinute(FunctionFactory &);
void registerFunctionToStartOfFiveMinutes(FunctionFactory &);
void registerFunctionToStartOfTenMinutes(FunctionFactory &);
void registerFunctionToStartOfFifteenMinutes(FunctionFactory &);
void registerFunctionToStartOfHour(FunctionFactory &);
void registerFunctionToStartOfInterval(FunctionFactory &);
void registerFunctionToStartOfISOYear(FunctionFactory &);
void registerFunctionToRelativeYearNum(FunctionFactory &);
void registerFunctionToRelativeQuarterNum(FunctionFactory &);
void registerFunctionToRelativeMonthNum(FunctionFactory &);
void registerFunctionToRelativeWeekNum(FunctionFactory &);
void registerFunctionToRelativeDayNum(FunctionFactory &);
void registerFunctionToRelativeHourNum(FunctionFactory &);
void registerFunctionToRelativeMinuteNum(FunctionFactory &);
void registerFunctionToRelativeSecondNum(FunctionFactory &);
void registerFunctionToTime(FunctionFactory &);
void registerFunctionNow(FunctionFactory &);
void registerFunctionNow64(FunctionFactory &);
void registerFunctionToday(FunctionFactory &);
void registerFunctionYesterday(FunctionFactory &);
void registerFunctionTimeSlot(FunctionFactory &);
void registerFunctionTimeSlots(FunctionFactory &);
void registerFunctionToYYYYMM(FunctionFactory &);
void registerFunctionToYYYYMMDD(FunctionFactory &);
void registerFunctionToYYYYMMDDhhmmss(FunctionFactory &);
void registerFunctionAddNanoseconds(FunctionFactory &);