Timestamp

An actual time-stamp from around 1960.

A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving the date and time of day, sometimes accurate to a small fraction of a second. Timestamps do not have to be based on some absolute notion of time, however. They can have any epoch, can be relative to any arbitrary time, such as the power-on time of a system or some arbitrary time in the past.

A distinction is sometimes made between the terms datestamp (DS), timestamp (TS) and date-timestamp (DTS):

  • Datestamp: A date, for example 2026-03-16 according to ISO 8601
  • Timestamp: A time of day, for example 04:43:20 (using the 24-hour clock)
  • Date-timestamp: Date and time, for example 2026-03-16T04:43:20 (ISO 8601)