The DateTime Structure

The DateTime structure is the most basic of the types that deal with dates and times. The DateTime structure, like most time-related structures in the .NET Framework, measures a specific moment in time as the number of ticks since midnight, January 1, 0001 CE. A tick is 100-nanoseconds; there are 10 million ticks per second.

The DateTime structure exposes a number of constructors that allow you to specify the year, month, day, hour, minute and second in various combinations, the number of ticks (all as Int64 structures) and optionally a Calendar or DateTime.Kind. By default, the DateTime uses the Gregorian calendar that is in use throughout most of the Western World, but the .NET Framework implements others, including the Hebrew, Japanese and Persian calendars. (If you need to work in an alternate, or multiple, calendars, search MSDN for System.Globalization.Calendar.)