Developer tools
Unix timestamp converter
Convert Unix timestamps to dates and back. Auto-detects seconds or milliseconds. Everything runs in your browser - nothing is uploaded.
Timestamp to date
- Local
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- UTC
- -
- ISO 8601
- -
- Relative
- -
Date to timestamp
- Seconds
- -
- Milliseconds
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How it works
A Unix timestamp is the number of seconds (or milliseconds) since the Unix epoch, midnight UTC on 1 January 1970. Paste one in and the converter shows the moment it represents in your local time and in UTC, with the day of the week and how long ago or how far ahead it is. It auto-detects whether your number is in seconds or milliseconds from its length, and you can override the unit if it guesses wrong.
Going the other way, pick a date and time and the converter gives you the timestamp back in both seconds and milliseconds, ready to copy. A live clock at the top shows the current Unix time ticking by, so you always have "now" to hand. Everything runs in your browser, so nothing you enter is uploaded, logged, or stored.
Example. The value 1700000000 has 10 digits, so it is read as seconds: that is Tue, 14 November 2023, 22:13:20 UTC. Paste 1700000000000 instead and the extra three digits mark it as milliseconds for the same instant. Use the reverse field to turn a chosen date into its seconds and milliseconds.
FAQ
What is a Unix timestamp?
It is a count of the time elapsed since the Unix epoch, 00:00:00 UTC on 1 January 1970, not counting leap seconds. It is most often given in seconds (a 10-digit number today) but is also common in milliseconds (13 digits), for example from JavaScript's Date.now(). It is a compact, timezone-free way to store an exact moment.
Seconds or milliseconds - how does it know?
It decides from the number of digits: roughly ten digits is read as seconds and thirteen as milliseconds, which covers the values you meet in practice. If your value falls outside the usual range, or you simply want the other reading, the seconds/milliseconds toggle lets you set the unit by hand and the result updates immediately.
Why are the local time and UTC different?
A timestamp marks one exact instant; how that instant reads on a clock depends on the time zone. The converter shows it in UTC, the global reference, and in your browser's local time zone, applying any daylight-saving offset in effect on that date, so you see both the universal value and what it meant where you are.
Is my data sent anywhere?
No. The conversion is plain arithmetic and date formatting that runs entirely in your browser with built-in functions. Nothing you type is uploaded, logged, or stored, and the tool keeps working offline once the page has loaded.