How to use
- Paste a timestamp (10 digits for seconds, 13 for milliseconds) or type a date like 2026-10-20 15:00.
- Read the local time, UTC, ISO 8601 string, seconds, milliseconds and how long ago it was.
- Press Now for the current timestamp, or paste a list to convert many at once.
Worked example: 1700000000
1700000000 seconds is 2023-11-14T22:13:20Z, which is 5:13 PM in New York (UTC-5) on 14 November 2023. As milliseconds it is 1700000000000.
Typing 2026-10-20 gives 1792454400 (midnight UTC), while 2026-10-20 09:00 in a UTC-5 zone is 1792504800.
Frequently asked questions
What is a Unix timestamp?
The number of seconds since 1 January 1970 00:00:00 UTC, ignoring leap seconds. Many systems use milliseconds instead, which is 1000 times larger.
How does it tell seconds from milliseconds?
By length: 13 or more digits are treated as milliseconds, fewer as seconds.
Which time zone is used for a typed date?
A date with a time but no zone is read in your local zone. A date alone is read as midnight UTC, matching JavaScript's Date parsing. Add Z or an offset to be explicit.
What happens in 2038?
Signed 32-bit timestamps overflow on 19 January 2038 (2147483647). This converter uses 64-bit numbers and is unaffected.
Are negative timestamps valid?
Yes, they represent dates before 1970.
Can I convert a column of timestamps?
Paste one per line in the list box; each is shown as seconds and ISO 8601.