Epoch date

In telecommunication, an epoch date is a date in history, chosen as the reference date from which time is measured.

Note 1: An example of an epoch date is the beginning instant of January 1, 1900, Universal Time, for Transmission Control Protocol/Internet Protocol (TCP/IP).

Note 2: TCP/IP programs exchange date or time-of-day information with time expressed as the number of seconds past the epoch date.

Source: from Federal Standard 1037C

See also epoch, era