What Is a Unix Timestamp?

A Unix timestamp is a single number that represents a moment in time: the count of seconds since January 1, 1970, 00:00:00 UTC (the "Unix epoch").

An example

1700000000 is a Unix timestamp. It corresponds to Tuesday, November 14, 2023, 22:13:20 UTC.

Why a number?

Representing time as one integer has big advantages:

• Unambiguous — no date formats, no locale confusion.
• Easy math — to add a day, add 86400 seconds.
• Compact and sortable — bigger number = later time.
• Time-zone neutral — it's always UTC; you format to local time only for display.

Seconds vs milliseconds

Watch out: Unix timestamps are in seconds, but JavaScript's Date.now() returns milliseconds. A 10-digit number is usually seconds; a 13-digit number is milliseconds.

Math.floor(Date.now() / 1000);  // current Unix timestamp (seconds)

Time zones

A Unix timestamp itself has no time zone — it's an absolute instant in UTC. The time zone only matters when you convert it to a human-readable date.

The Year 2038 problem

Systems that store the timestamp in a signed 32-bit integer overflow on January 19, 2038. Modern systems use 64-bit integers, which are safe for billions of years. More in epoch time explained.

Convert one

Paste any timestamp or date into the timestamp converter to translate between Unix time and human-readable dates.