Convert Unix timestamps to dates (and back)
Convert a Unix timestamp to a date or a date to a timestamp; shows UTC, local time, ISO 8601 and relative time.
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A Unix timestamp counts seconds since 1 January 1970 00:00:00 UTC. Logs, JWTs, databases and APIs use it because it is a single integer with no time zone to argue about. The catch is that humans cannot read it, and JavaScript uses milliseconds while most other systems use seconds, so 1789905600 and 1789905600000 look different but are the same instant.
Paste a number and the tool detects whether it is seconds or milliseconds (anything of 100 billion or more is treated as milliseconds, which covers every date after 1973 in milliseconds and before the year 5138 in seconds). Paste a date instead, such as 2026-09-20, 2026-09-20T12:00:00+04:00 or "Sep 20 2026 12:00 GMT+4", and get the timestamp. Every conversion shows UTC, your local time, ISO 8601 and a relative phrase like "in 3 days".
The Now button inserts the current time from your device. Local time uses your browser's time zone; date-only inputs like 2026-09-20 are read as midnight UTC, as the ISO standard specifies.
How to use it
- Paste a timestamp (seconds or milliseconds) or a date string, or click Now.
- Leave the unit on Auto unless you know the number is in a specific unit and it is being misread.
- Read the Unix seconds, milliseconds, ISO 8601, UTC, local and relative values.
- Copy the line you need or download all of them.
Frequently asked questions
Why does 2026-09-20 show as the evening of 19 September in my local time?
A date without a time is interpreted as 00:00 UTC. If you are west of Greenwich, that instant falls on the previous local evening. Add a time and offset (2026-09-20T00:00:00-05:00) to pin it to your zone.
What is the year 2038 problem?
Systems that store the timestamp in a signed 32-bit integer overflow at 2147483647, which is 19 January 2038 03:14:07 UTC. Modern systems use 64 bits and are unaffected. The converter itself handles dates far beyond that.
Which timestamp does JavaScript's Date.now() return?
Milliseconds. Divide by 1000 (and floor) for seconds, which is what Unix tools, Python's time.time() and JWT claims use.
Are negative timestamps valid?
Yes; they represent dates before 1970. -86400 is 31 December 1969.
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