| AddWeeks | Adds a Floating Point amount of Weeks to a Given Date/Time. |
| AgeAtDateInWeeks | Returns the Age (in weeks) of a "person" given their Date of Birth (DOB) and the Date of Reference (DT). |
| 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. |
| Date2ISOWeekEnhStr | Returns Date as a Enhanced Format for ISO Calendar Week/Day: YYYY-Www-D where YYYY is year, 'W' is literal, ww is weekno and D is the ISO Day of Week - Monday is First Day. |
| Date2ISOWeekNo | Converts Dates into a Week No and Year according to ISO-8601. |
| Date2ISOWeekOnlyEnhStr | Returns Date as a Enhanced Format for ISO Calendar Week: YYYY-Www where YYYY is year, 'W' is literal, ww is weekno. |
| Date2ISOWeekOnlyStr | Returns Date as a Basic Format for ISO Calendar Week: YYYYWww where YYYY is year, 'W' is literal, ww is weekno. |
| Date2ISOWeekStr | Returns Date as a Basic Format for ISO Calendar Week/Day: YYYYWwwD where YYYY is year, 'W' is literal, ww is weekno and D is the ISO Day of Week - Monday is First Day. |
| Date2WeekNo | Converts Dates into a Week No in the Current Year. |
| DatesInSameWeekNo | Returns true if the two Dates are in the same WeekNo. |
| DOW2ISODOW | Converts a Delphi Day of Week into an ISO-8601 Day Of Week. |
| 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. |
| ExactWeeksApart | Returns the Exact Number of Weeks between DT2 and DT1. |
| GetFirstMondayOfYear | Returns First Monday of the Year, for a given Year. |
| GetFirstSundayOfYear | Returns First Sunday of the Year, for a given 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. |
| 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. |
| SubtractWeeks | Subtracts a Floating Point amount of Weeks from a Given Date/Time. |
| ThisISOWeekNo | Returns the ISO-8601 WeekNo of the current Date (System Date). |
| ThisWeekNo | Returns the WeekNo of the current Date (System Date). |
| 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. |