What is a Unix Timestamp?

A Unix timestamp is the number of seconds elapsed since the Unix epoch — midnight UTC on 1 January 1970. It is the universal way computers store and exchange time.

Definition

Unix timestamps are timezone-independent integers. The timestamp 1700000000 represents the same instant everywhere in the world: 14 November 2023 at 22:13:20 UTC. Convert to local time by adding the UTC offset for your timezone.

Why Use Timestamps?

  • Unambiguous — no timezone, no daylight saving ambiguity
  • Simple arithmetic — subtract two timestamps to get elapsed seconds
  • Universal — supported by every programming language and database
  • Compact — a single integer rather than a formatted string

Millisecond Timestamps

JavaScript and many APIs use milliseconds since epoch (multiply seconds by 1000). A 13-digit number like 1700000000000 is a millisecond timestamp; a 10-digit number is seconds.

The Year 2038 Problem

32-bit signed integers overflow on 19 January 2038 at 03:14:07 UTC. Modern systems use 64-bit integers, which won't overflow for billions of years.

Convert Unix timestamps to human-readable dates instantly: Open Unix Timestamp Converter →

Frequently Asked Questions

What is the Unix epoch?

The Unix epoch is 00:00:00 UTC on 1 January 1970 — the reference point from which all Unix timestamps are counted.

How do I get the current Unix timestamp?

In JavaScript: Math.floor(Date.now() / 1000). In Python: import time; time.time(). In Bash: date +%s.