Unix Timestamp Converter
Translate epoch seconds to ISO-8601 UTC strings or parse ISO dates into Unix time.
Unix timestamp converter
Convert epoch seconds ↔ ISO-8601 UTC strings.
What the Unix timestamp converter does
Unix time here is a count of seconds since 1970-01-01 00:00:00 UTC, not counting leap seconds. The page turns that integer into an ISO-8601 UTC string, or parses an ISO string back into seconds. JavaScript’s Date.now() is milliseconds; divide by 1000 before you paste it.
Values are interpreted as UTC. A timestamp does not carry a time zone. To see the same instant in Asia/Kolkata or another zone, use the time-zone converter after you have a civil time.
How to use it
- Choose Unix → ISO or ISO → Unix.
- Paste seconds, or an ISO-8601 string such as 2026-01-01T00:00:00.000Z.
- If you copied a 13-digit value, it is milliseconds. Divide by 1000 first.
- Copy the result. “Use now” fills the box with the current time in seconds.
The conversion runs in the browser. The value is not uploaded.
Questions
Why is my date a day off?
A millisecond value pasted as seconds lands centuries ahead, and a local clock time without a Z is not the same instant as UTC. Use seconds and an explicit UTC ISO string.
Does this count leap seconds?
No. It uses the common POSIX scale, the same one JavaScript dates use.
Can I convert a future timestamp?
Yes. The math does not care whether the instant is in the past or the future.
Frequently Asked Questions
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