Convert between Unix timestamps and human-readable dates across timezones.
Enter a timestamp to see the converted date.
Pick a date and time to convert.
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This converter works in both directions at once: type a Unix timestamp and see it as ISO 8601, your chosen timezone, and a relative time ("3 hours ago"); or pick a date and time and see the equivalent Unix timestamp in both seconds and milliseconds. A live clock at the top shows the current Unix timestamp, updating every second.
Input
1700000000
Converted output
ISO 8601: 2023-11-14T22:13:20.000Z UTC: Tue, 14 Nov 2023 22:13:20 GMT
How does it know if my timestamp is in seconds or milliseconds?
By size: if the number you enter is greater than 9,999,999,999 it is treated as milliseconds; otherwise it is treated as seconds and multiplied by 1000 internally. This threshold works because Unix seconds values won't pass that number until the year 2286, so any larger number is assumed to already be milliseconds.
Which timezones are supported?
Eight fixed options: UTC, IST (Asia/Kolkata), EST (America/New_York), PST (America/Los_Angeles), GMT (Europe/London), CET (Europe/Berlin), JST (Asia/Tokyo), and AEST (Australia/Sydney). Selecting one updates the formatted date shown for both conversion directions using that IANA timezone.
What does the "Relative" time mean?
A human-readable distance from now, computed from the difference between the parsed timestamp and the current time on your device — e.g. "3 hours ago" or "2 days from now". It is calculated client-side after the page mounts, using your local clock.
Why does the current timestamp show "…" for a moment?
The live clock only starts after the page mounts in your browser — rendering a timestamp during server-side prerendering would bake a stale build-time value into the page and cause a hydration mismatch, so it intentionally shows a placeholder for a fraction of a second first.
