Quantity Number a number with no scale Bytecount a number of bytes Currency a number of dollars (or other currency units) Currencies a collection of currency values Date a diurnal period in the history/future of the Earth Time a number of seconds since midnight - time within a 24:00 clock Moment a date or a date and a time Period a range of moments Duration a number of seconds (or minutes, hours, days, months, years) Weekday OrdinalWeekdayOfMonth DayOfMonth MonthOfYear DayMonthOfYear Year