| AddCalendarMonths | Adds a Specified Number of Calendar Months to a Given Date/Time. |
| AddDays | Adds a Floating Point amount of Days to a Given Date/Time. |
| AddFortnights | Adds a Floating Point amount of Fortnights to a Given Date/Time. |
| AddHrs | Adds a Floating Point amount of Hours to a Given Date/Time. |
| AddMins | Adds a Floating Point amount of Minutes to a Given Date/Time. |
| AddMonths | Adds a Floating Point amount of Months to a Given Date/Time. |
| AddQuarters | Adds a Floating Point amount of Quarters to a Given Date/Time. |
| AddSecs | Adds a Floating Point amount of Seconds to a Given Date/Time. |
| AddSemesters | Adds a Floating Point amount of Semesters to a Given Date/Time. |
| AddWeeks | Adds a Floating Point amount of Weeks to a Given Date/Time. |
| AddYrs | Adds a Floating Point amount of Years to a Given Date/Time. |
| AdjustDateYear | Adjusts the date so that it has the Year specified. |
| AgeAtDate | Returns the Age (in years) of a "person" given their Date of Birth (DOB) and the Date of Reference (DT). |
| AgeAtDateInMonths | Returns the Age (in months) of a "person" given their Date of Birth (DOB) and the Date of Reference (DT). |
| AgeAtDateInWeeks | Returns the Age (in weeks) of a "person" given their Date of Birth (DOB) and the Date of Reference (DT). |
| AgeNow | Returns the current Age (in years) of a "person" given their Date of Birth (DOB) using the System Date. |
| AgeNowInMonths | Returns the current Age (in months) of a "person" given their Date of Birth (DOB) using the System Date. |
| AgeNowInWeeks | Returns the current Age (in weeks) of a "person" given their Date of Birth (DOB) using the System Date. |
| CalendarMonthsApart | Returns the Number of Calendar Months between DT2 and DT1. |
| CalendarWeeksApart | Returns the Number of Calendar Weeks between DT2 and DT1. |
| Date2ISOWeekNo | Converts Dates into a Week No and Year according to ISO-8601. |
| Date2WeekNo | Converts Dates into a Week No in the Current Year. |
| DatesInSameMonth | Returns true if both DateTimes refer to the same Calendar Month, can have different years. |
| DatesInSameMonthYear | Returns true if both DateTimes refer to the exact same Month, cannot have different years. |
| DatesInSameWeekNo | Returns true if the two Dates are in the same WeekNo. |
| DatesInSameYear | Returns true if both DateTimes refer to the same Year. |
| DayOfMonth2Date | Returns the Given Occurrence (Day of Month) of a Day of Week in a given Month/Year. |
| DayOfYear | Returns the Day Number in the Year represented by the given Date. |
| DaysApart | Returns the Number of Days between DT2 and DT1. |
| DaysInMonth | Returns the number of days in the Month represented by the given Date. |
| DaysInThisMonth | Returns the number of days in the current Month. |
| DaysInYear | Returns the number of days in the Year represented by the given Date. |
| DaysLeftInMonth | Returns the Number of days left in the Month represented by the given Date. |
| DaysLeftInThisMonth | Returns the number of days left in the current Month. |
| DaysLeftInThisYear | Returns the number of days left in this Year. |
| DaysLeftInYear | Returns the number of days left in the Year represented by the given Date. |
| DOW2ISODOW | Converts a Delphi Day of Week into an ISO-8601 Day Of Week. |
| DOWsInMonth | Returns the number of the specified Day of Week in the Given Month/Year. |
| DOWsInRange | Returns the number of the specified Day of Week in the Given Date Range (inclusive). |
| DWY2Date | Returns the Date for a given Day of Week, a given WeekNo, and the given Year, assuming that the Start of the Week is Sunday, and that DOW uses 1 for Sunday. |
| EndOfISOWeek | Returns the End of the week containing given Date/Time, assumes that the End of the Week is Sunday according to ISO-8601 - Time portion preserved. |
| EndOfISOWeekNo | Returns the End of the Week for the given ISO-8601 WeekNo in the given year. |
| EndOfWeek | Returns the End of the week containing given Date/Time, assumes that the End of the Week is Saturday - Time portion preserved. |
| EndOfWeekNo | Returns the End of the Week for the given WeekNo in the given year, assuming that the End of the Week is Saturday. |
| ESBToday | A Speed Optimised Routine to get the Current Date. |
| ESBTomorrow | A Speed Optimised Routine to get the Tomorrow's Date. |
| ESBYesterday | A Speed Optimised Routine to get the Yesterday's Date. |
| ExactWeeksApart | Returns the Exact Number of Weeks between DT2 and DT1. |
| GetChristmasDay | Returns Christmas Day, for a given Year. |
| GetDateTimeStamp | Returns the current date/time as a string in the Format of: YYYYMMDD-HHMMSSmmm. |
| GetEasterSunday | Returns the Date of Easter Sunday for given Year - based on current Calendar. |
| GetEpact | Return the Epact, which is a measure of the age of the moon (ie the number of days that have passed since an "official" new moon) on a particular date. |
| GetFirstDayOfMonth | Returns First Day of the Month, for a given Date/Time - Time portion preserved. |
| GetFirstDayOfQuarter | Returns First Day of the Quarter, for a given Date/Time - Time portion, preserved or Returns First Day of the Quarter, for a given Quarter and Year. |
| GetFirstDayOfYear | Returns First Day of the Year, for a given Year. |
| GetFirstMondayOfYear | Returns First Monday of the Year, for a given Year. |
| GetFirstSundayOfYear | Returns First Sunday of the Year, for a given Year. |
| GetGoldenNumber | Returns the GoldenNumber for a given Year. |
| GetGoodFriday | Returns the Date of Good Friday for given Year - based on current Calendar. |
| GetLastDayOfMonth | Returns Last Day of the Month, for a given Date/Time - Time portion preserved. |
| GetLastDayOfQuarter | Returns Last Day of the Quarter, for a given Date/Time - Time portion preserved or Returns Last Day of the Quarter, for a given Quarter and Year. |
| GetLastDayOfYear | Returns Last Day of the Year, for a given Year. |
| IsLeapYear | Is given Year a Leap Year. |
| ISODayOfWeek | Returns Day Of Week According to ISO-8601 which has Monday as 1 and Sunday as 7. |
| ISODOW2DOW | Converts an ISO-8601 Day of Week into a Delphi Day Of Week. |
| ISOWeeksApart | Returns the Number of ISO Weeks between DT2 and DT1. |
| ISOWeeksInYear | Most years have 52 weeks, but years that start on a Thursday and leap years that start on a Wednesday (or Thursday) have 53 weeks. |
| ISOYWD2Date | Returns the Date for a given Day of Week, a given WeekNo, and the given Year, as defined in ISO-8601. |
| IsWorkingDay | Returns True if the specified Date is a Working Day. |
| MinutesApart | Returns the number of whole minutes apart the two times are (date portion ignored) and DT1 is assumed to be before DT2. |
| MS2TimeStr | Converts a time in MilliSeconds to a string of the form 'H:MM:SS.mmm'. |
| OptDate | A Speed Optimised Routine to get the Current Date. |
| OptDayOfYear | Returns the Day Number in the Year represented by the given Date. |
| OptDaysLeftInThisYear | Returns the number of days left in this Year. |
| OptDaysLeftInYear | Returns the number of days left in the Year represented by the given Date. |
| OptThisDayOfYear | Returns the Day Number in this Year represented by today. |
| StartOfISOWeek | Returns the Start of the week containing given Date/Time, assumes that the Start of the Week is Monday according to ISO-8601 - Time portion preserved. |
| StartOfISOWeekNo | Returns the Start of the Week for the given ISO-8601 WeekNo in the given year. |
| StartOfWeek | Returns the Start of the week containing given Date/Time, assumes that the Start of the Week is Sunday - Time portion preserved. |
| StartOfWeekNo | Returns the Start of the Week for the given WeekNo in the given year, assuming that the Start of the Week is Sunday. |
| SubtractDays | Subtracts a Floating Point amount of Days from a Given Date/Time. |
| SubtractFortnights | Subtracts a Floating Point amount of Fortnights from a Given Date/Time. |
| SubtractHrs | Subtracts a Floating Point amount of Hours from a Given Date/Time. |
| SubtractMins | Subtracts a Floating Point amount of Minutes from a Given Date/Time. |
| SubtractMonths | Subtracts a Floating Point amount of Months from a Given Date/Time. |
| SubtractQuarters | Subtracts a Floating Point amount of Quarters from a Given Date/Time. |
| SubtractSecs | Subtracts a Floating Point amount of Seconds from a Given Date/Time. |
| SubtractSemesters | Subtracts a Floating Point amount of Semesters from a Given Date/Time. |
| SubtractWeeks | Subtracts a Floating Point amount of Weeks from a Given Date/Time. |
| SubtractYrs | Subtracts a Floating Point amount of Years from a Given Date/Time. |
| ThisDayOfYear | Returns the Day Number in this Year represented by today. |
| ThisISOWeekNo | Returns the ISO-8601 WeekNo of the current Date (System Date). |
| ThisWeekNo | Returns the WeekNo of the current Date (System Date). |
| TimeApartInDays | Returns the decimal number of Days apart the two date/times are. |
| TimeApartInFortnights | Returns the decimal number of fortnights apart the two date/times are. |
| TimeApartInHrs | Returns the decimal number of hours apart the two date/times are. |
| TimeApartInMins | Returns the decimal number of Minutes apart the two date/times are. |
| TimeApartInSecs | Returns the decimal number of Seconds apart the two date/times are. |
| TimeApartInWeeks | Returns the decimal number of Weeks apart the two date/times are. |
| WeekDaysInMonth | Returns the number of the Week Days (Mon through Fri) in the Given Month/Year. |
| WeekendDaysInMonth | Returns the number of the WeekEnd Days (Sat & Sun) in the Given Month/Year. |
| WeekNosApart | Returns true No of Weeks, based on WeekNo, that the two dates are apart. |
| WeeksApart | Returns the Number of Weeks between DT2 and DT1. |
| WhichQuarter | Returns 1 if Date in Jan through Mar, 2 if Date in Apr through Jun, 3 if Date in Jul through Sep, 4 if Date in Oct through Dec. |
| WhichSemester | Returns 1 if Date in Jan through Jun or 2 if Date in Jul through Dec. |
| iff | Performs an if that can be used in Expressions. |
| SwapXY | Swap 2 Values using a Temp Value. |