Unix Timestamp Converter
Convert Unix timestamps to dates and back, in UTC and your local timezone.
Timestamp
Private by design. Everything runs locally in your browser. Your input is never uploaded, logged or stored on a server.
Frequently asked questions
What is a Unix timestamp?
The number of seconds elapsed since the Unix epoch, 1 January 1970 at 00:00:00 UTC. It identifies an instant without reference to any timezone.
Is my timestamp in seconds or milliseconds?
Ten digits is seconds and thirteen is milliseconds for any current date. The converter detects this automatically and shows both interpretations.
What is the year 2038 problem?
A signed 32-bit timestamp overflows on 19 January 2038. Systems storing time in a 32-bit integer will wrap to 1901. Modern platforms use 64-bit values and are unaffected.
Which timezone does the output use?
All three are shown: UTC, ISO 8601 with offset, and your device local timezone as reported by the browser.
About the Unix Timestamp Converter
A Unix timestamp counts seconds since 1970-01-01 00:00:00 UTC, ignoring leap seconds. It is timezone-free by definition, which is exactly why it is used for storage and transport — a timestamp means the same instant everywhere, and only becomes ambiguous when rendered.
Units are the recurring problem. Unix tools and most APIs use seconds; JavaScript Date.now(), Java and many log formats use milliseconds. A ten-digit number is seconds, thirteen digits is milliseconds. This converter detects the unit automatically and shows both, so a date in 1970 or in the year 55000 immediately tells you the unit was wrong.
Every conversion is shown in UTC, ISO 8601 and your browser timezone at once, because most timestamp bugs are really timezone bugs discovered late.