Unix Timestamp Converter

Convert between Unix epoch and human-readable dates. Auto-detects seconds vs milliseconds, accepts ISO 8601 dates, and shows the result in your local timezone and UTC simultaneously.

Current epoch
s · ms

About Unix Time

Unix time (also called epoch time or POSIX time) is the number of seconds that have elapsed since 1970-01-01 00:00:00 UTC. It is the de facto standard for storing and exchanging timestamps in computer systems because it is timezone-independent, monotonic (ignoring NTP corrections), and trivial to do arithmetic on.

Common Units & Formats

Year 2038 (Y2K38)

Signed 32-bit Unix timestamps overflow on 19 January 2038 at 03:14:07 UTC. Systems still using time_t as a 32-bit integer — embedded devices, old filesystems, some MySQL columns — will wrap to negative numbers and break. Most modern systems have moved to 64-bit time, which is good for the next ~292 billion years.

Frequently Asked Questions

A Unix timestamp (or epoch time) is the number of seconds elapsed since 1970-01-01 00:00:00 UTC, not counting leap seconds. It's the most common machine-friendly way to represent a point in time and is timezone-independent.
By magnitude. A 10-digit number (around 1.7 billion in 2024+) is seconds. A 13-digit number (around 1.7 trillion) is milliseconds. 16 digits is microseconds, 19 is nanoseconds. This tool auto-detects based on length.
Signed 32-bit timestamps overflow at 03:14:07 UTC on 19 January 2038 (2^31 - 1 seconds). Systems still using int32 for time will wrap to negative numbers, breaking date logic. Modern systems use 64-bit integers (good for ~292 billion years), so this is mostly a concern for legacy embedded systems and old file formats.
Almost always a timezone mismatch. Unix timestamps are always UTC; if a system displays them in local time, you may see an offset. This tool shows your local time, UTC, and ISO 8601 simultaneously so you can spot the difference instantly.
No, and neither does Unix epoch by design. POSIX explicitly defines epoch time as ignoring leap seconds (every day is exactly 86400 seconds). Astronomical UTC, which does include leap seconds, can differ from POSIX time by a few dozen seconds.
Copied to clipboard!