Developer & data
Unix timestamp converter
Convert Unix seconds or milliseconds and offset-aware ISO dates.
Runs in your browser · No file or text uploads
Preparing your tool…
What Unix timestamp converter helps you do
Read timestamps in logs and APIs, with UTC and an explicitly selected IANA time zone shown side by side.
How to use it
- Choose the direction and seconds or milliseconds.
- Enter a timestamp or an ISO date containing a time-zone offset.
- Compare UTC and the selected zone.
Input and output example
INPUT
1767225600 secondsOUTPUT
2026-01-01T00:00:00.000Z
Supported formats and limits
- Supports JavaScript Date values whose milliseconds are safe integers. Seconds allow up to three decimal places; milliseconds require integers.
- ISO date input must include Z or an offset such as +01:00. Leap-second :60 and exponent notation for Unix values are unsupported.
How the result is calculated
Unix time measures elapsed time since 1970-01-01T00:00:00Z; zero is valid. UTC is the default. Zoned output uses ISO-style numeric dates and the browser’s Intl/IANA time-zone data, including daylight-saving rules. Source: https://www.iana.org/time-zones. The browser does not expose its database version or update date.
Frequently asked questions
Why does a 13-digit number show an unexpected date?
It may be a millisecond value. This tool does not guess the unit, so check the unit selector.
Does my computer’s default time zone affect the result?
No. Input dates need an explicit offset and output uses UTC plus your selected IANA zone. Time-zone database updates still depend on your browser and operating system.