Unix Timestamp Converter
Convert Unix timestamps (epoch) to human-readable dates and ISO 8601, in any timezone. Runs in your browser.
Runs entirely in your browser. Nothing is sent to our servers.
About this tool
A Unix timestamp (also called Unix time or epoch time) is the number of seconds elapsed since January 1, 1970 UTC. It's the time format underlying most operating systems, programming languages, and databases. This tool converts between Unix timestamps and human-readable dates in any timezone, entirely in your browser.
Seconds vs milliseconds
Unix timestamps come in two common flavours: seconds (10
digits for current dates, used by most C-style APIs and databases) and
milliseconds (13 digits, used by JavaScript's
Date.now() and most web APIs). This tool auto-detects which
one you've pasted by checking the digit count.
The 2038 problem
Systems that store Unix timestamps as a signed 32-bit integer will overflow on January 19, 2038 at 03:14:07 UTC. Modern systems use 64-bit timestamps, which won't overflow for several hundred billion years. If you're working with legacy code, check the size of the underlying type — it matters.
Frequently asked questions
- Why does my timestamp show a different time than expected?
- Almost always a timezone issue. The same Unix timestamp represents the same instant in time everywhere on Earth — but it displays differently depending on the viewer's timezone. Use the timezone dropdown to confirm what your timestamp actually means.
- What about leap seconds?
- Unix time ignores leap seconds — there have been 27 of them since 1972, all skipped. For most applications this doesn't matter; for high-precision astronomy or some scientific timing, it does, and you'd use TAI or UT1 instead.
- Can I paste a date in a non-ISO format?
- Yes, anything the browser's
Date.parse()recognizes will work — RFC 2822 dates, RFC 3339, common US formats. When ambiguous, prefer ISO 8601 (2026-05-17T14:30:00Z) for unambiguous parsing. - Why do some timestamps in 1969 produce negative numbers?
- Because Unix time counts from January 1, 1970 — anything before that is a negative number of seconds away from the epoch.
Last updated: May 17, 2026