Unix Timestamp Converter
Convert Unix timestamps in seconds or milliseconds to UTC and local dates, and dates back to timestamps.
How to use the Unix Timestamp Converter
- To convert a timestamp, paste it into “Unix timestamp”. Leave the unit on Auto-detect or choose seconds or milliseconds.
- Read the UTC, ISO 8601 and local-time results and copy any line with its Copy button.
- To convert a date, pick a date and time, choose whether it is your local time or UTC, and read the seconds and milliseconds.
- Use “Use current time” to fill in the present moment in either panel.
Good to know
- A Unix timestamp counts time since 1970-01-01 00:00:00 UTC. It has no time zone; only the displayed date does.
- Auto-detect treats values with an absolute value of 100,000,000,000 (1e11) or more as milliseconds and anything smaller as seconds. Values that could plausibly be either trigger a visible warning, and you can override the unit.
- Supported range is the JavaScript Date range, ±8,640,000,000,000,000 milliseconds (years −271821 to 275760). Decimal seconds are rounded to the nearest millisecond.
- Local time uses the time zone of your browser. Date and time values that do not exist, such as 30 February or a time skipped by a daylight-saving change, are rejected instead of being shifted.
Examples
- Seconds
- 1700000000 → Tue, 14 Nov 2023 22:13:20 GMT (2023-11-14T22:13:20.000Z)
- Milliseconds
- 1700000000000 → the same instant. Auto-detect reads 13-digit values as milliseconds.
- Before 1970
- -86400 → Wed, 31 Dec 1969 00:00:00 GMT. Negative timestamps count backwards from the epoch.
Frequently asked questions
How do I tell seconds from milliseconds?
Current timestamps in seconds have 10 digits (about 1.7 billion); in milliseconds they have 13 digits. If a date comes out in January 1970, you probably passed seconds as milliseconds.
Does this handle leap seconds?
No. Unix time ignores leap seconds, every day is exactly 86,400 seconds, which is also how JavaScript dates work.
Why does the local time differ from the UTC time?
Local time applies your browser's time zone offset, including daylight saving where it applies. UTC is the same everywhere.
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