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Unix Timestamp Converter

Convert Unix timestamps to dates

About Unix Timestamp Converter

Unix Timestamp Converter turns a Unix timestamp into a date and a date back into a timestamp. The unit is read from the number of digits (up to 11 for seconds, 12 to 14 for milliseconds, 15 to 17 for microseconds, 18 to 20 for nanoseconds), and the result always names the unit it used. Each result gives the ISO 8601 date, the UTC date, the date in the time zone you pick (your own by default), how long ago or ahead it is, and the value as seconds and as milliseconds. UTC and zone dates use the US format, such as October 11, 2025, 2:23:00 PM. Negative values (before 1970) work, and decimals are read for seconds only. A time skipped by daylight saving time is refused, and a repeated one is flagged.

Example

Output of the page's own conversion code for a 13-digit value with America/New_York picked; the Relative line is left out because it depends on today's date.

Unix timestamp

1700000000000

Result box

Read as milliseconds
ISO 8601: 2023-11-14T22:13:20Z
UTC: November 14, 2023, 10:13:20 PM
America/New York: November 14, 2023, 5:13:20 PM (UTC−05:00)
Seconds: 1700000000  Milliseconds: 1700000000000

How to convert a Unix timestamp to a date and back

  1. 1Pick a zone in "Time zone (for the date field and the result)"; your own zone comes first.
  2. 2Type a timestamp in "Unix timestamp" and click the "Convert" button next to it, or click "Use current time".
  3. 3To go the other way, set "Date and time" and click its "Convert" button.
  4. 4Read the box below: "Read as" names the unit, followed by the ISO 8601 date, UTC, your chosen zone, the relative time, and the value as seconds and as milliseconds.

Formats and limits

Units read
Seconds (up to 11 digits), milliseconds (12 to 14), microseconds (15 to 17), nanoseconds (18 to 20)
Date range
The JavaScript date range, from year -271821 to year 275760
Precision
Milliseconds; microseconds and nanoseconds are truncated, and a decimal part counts for seconds only
Time zones
Your browser's list of IANA zones, shown under their current names such as Asia/Kolkata
Date to timestamp
Whole seconds, read in the zone you picked

Where your dates are converted

Every conversion is computed by the page with your browser's own time-zone data; the timestamps and dates you enter are not sent to our servers. If an error message is shown, that message is sent to our error log with the tool's name and your browser's name and version, long numbers replaced by a placeholder, so that we can fix recurring problems.

Frequently asked questions

Can it tell seconds from milliseconds?

Yes, by counting digits: 1700000000 has 10 digits and is read as seconds, 1700000000000 has 13 and is read as milliseconds. The result starts with Read as and the unit, so a date in 1970 or far in the future points to a wrong unit.

Is the date field read in UTC?

No. It is read in the zone selected in the list, which is your own by default. A time skipped when daylight saving time starts is refused with a message, and a time that occurs twice is read as the first one, with a note giving the second.

Can I convert dates before 1970?

Yes. Enter a negative timestamp: -86400 gives 1969-12-31T00:00:00Z, which is December 31, 1969, 12:00:00 AM in UTC. Dates before year 1 are shown in the results, but the date field stays empty because it cannot hold them.

Does it accept decimal timestamps like 1700000000.5?

Yes, for seconds: 1700000000.5, as returned by Python's time.time(), is read to the millisecond. A decimal part after a millisecond, microsecond, or nanosecond value is ignored.

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