Date & time
Unix Timestamp Converter
Convert timestamps to readable dates (UTC/local), and convert dates back to Unix seconds or milliseconds. Runs locally in your browser.
Display timezone
Changes how dates are shown in the results. Default is Local.
Timestamp → date
Paste a Unix timestamp and choose seconds vs milliseconds (or let the tool auto-detect).
UTC ISO 8601
2023-11-14T22:13:20.000Z
Local time
2023-11-14 22:13:20.000 (UTC+00:00)
In Local
2023-11-14 22:13:20.000 (UTC)
RFC 1123 (UTC)
Tue, 14 Nov 2023 22:13:20 GMT
Date → timestamp
Paste an ISO date/time. If you omit a timezone, choose whether to interpret it as local time or UTC.
Unix seconds
1,770,976,800
Unix milliseconds
1,770,976,800,000
UTC ISO 8601 (normalized)
2026-02-13T10:00:00.000Z
In Local
2026-02-13 10:00:00.000 (UTC)
Seconds vs milliseconds
Unix timestamps are often stored in seconds (10 digits) or milliseconds (13 digits). If your date looks ~1000× too far in the future/past, you probably picked the wrong unit.
UTC vs local time
2026-02-13T10:00:00Z is explicit UTC. A string without timezone (like 2026-02-13T10:00:00) is ambiguous, so the tool lets you choose how to interpret it.
Common formats
- 1700000000 (Unix seconds)
- 1700000000000 (Unix milliseconds)
- 2026-02-13T10:00:00Z (ISO 8601 UTC)
- 2026-02-13T10:00:00-05:00 (ISO 8601 with offset)
How it works
The converter normalizes your input as seconds or milliseconds, turns it into a JS Date in UTC, then renders readable strings for local time, UTC, and any chosen timezone.
- Auto-detect treats 13+ digits as milliseconds; switch units manually if your source is fixed.
- Uses your browser clock and time zone data; results can drift if the system clock is off.
Quick examples
If you paste fractional seconds, the tool keeps millisecond precision when converting.
Mini FAQ
Does it handle leap seconds?
No. JavaScript Date ignores leap seconds, matching most web APIs.
What if the timestamp is negative?
Negative values work and represent dates before 1970.
Why do outputs differ by zone?
The underlying instant is the same; formatting changes offset and label only.
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