What is Epoch / Unix Time?

Unix time (epoch time) is a way of representing a point in time as the number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970, ignoring leap seconds. It is timezone-independent and easy to compare or store.

Many systems use milliseconds instead of seconds. The classic 32-bit signed representation overflows in 2038 (the "Year 2038 problem"), which is why 64-bit timestamps are now standard.

Key points

  • Counts seconds since 1 Jan 1970 00:00:00 UTC.
  • Timezone-independent, which makes comparisons simple.
  • Many systems use milliseconds rather than seconds.
  • The 32-bit form overflows in 2038 (the Year 2038 problem).

Example

1700000000 =
Tue, 14 Nov 2023 22:13:20 UTC

Common uses

  • Storing timestamps in databases
  • Comparing and sorting times
  • Token expiry (the JWT exp claim)
  • Logging and ordering events

Work with Epoch / Unix Time directly in your browser.

Open the Timestamp Converter

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