Developer Tools
Unix timestamp converter
Convert Unix seconds or milliseconds to ISO 8601 and local time, or an offset-aware date to Unix. Supports negative timestamps and validates units.
Integer seconds or milliseconds. For dates use ISO 8601 with Z or an offset; the time zone is never guessed.
What this tool does
Check technical log dates without confusing seconds and milliseconds. Output identifies UTC, the device time zone and the same instant in both units.
How to use it
- Select seconds, milliseconds or ISO 8601.
- Enter an integer or a complete date with Z or an offset.
- Convert and compare ISO, local time zone and both Unix units.
Verifiable example
- Input
- Unix: -1 second.
- Expected result
- 1969-12-31T23:59:59.000Z; -1000 milliseconds.
Limitations to review
- Integer Unix input; dates within ±8.64e15 ms. ISO input requires a four-digit year and explicit offset.
- Does not parse month names, abbreviated zones or ambiguous local dates; leap seconds are not modeled.
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