YUCTS Tools

Unix Timestamp Converter

Convert Unix timestamps to dates and dates to timestamps. Seconds, milliseconds, microseconds or nanoseconds, ISO 8601 with IANA time zones, values past 2038 and negative values before 1970.

  • Runs in your browser (no upload)
Current Unix time—

Unix time → date and time

Negative values (before 1970) and decimals such as 1700000000.5 are accepted.

Result

Detected as "Seconds" from the number of digits. Choose the unit if this is wrong.

ISO 8601 (UTC)
2038-01-19T03:14:08Z
ISO 8601 (with offset)
2038-01-19T03:14:08+00:00
HTTP date (RFC 9110)
Tue, 19 Jan 2038 03:14:08 GMT
Unix seconds
2147483648
Unix milliseconds
2147483648000
This time is outside the range of a signed 32-bit time_t (1901-12-13T20:45:52Z to 2038-01-19T03:14:07Z). Older systems may mishandle it (the "Year 2038 problem").

Date and time → Unix time

Result

Unix seconds
2147483648
Unix milliseconds
2147483648000
ISO 8601 (UTC)
2038-01-19T03:14:08Z
ISO 8601 (with offset)
2038-01-19T03:14:08+00:00

How to use

  1. Choose a time zone (your browser's zone by default).
  2. Enter a Unix timestamp. The unit is detected from the number of digits, or you can choose seconds, milliseconds and so on.
  3. See ISO 8601 (UTC and with offset), the date and time in the chosen zone, and Unix seconds and milliseconds. Below, turn a date and time into a timestamp.

FAQ

How are seconds and milliseconds told apart?

By the number of digits in the integer part: up to 11 digits are seconds, up to 14 milliseconds, up to 17 microseconds, more than that nanoseconds. Choose the unit when the guess is wrong, for example 12-digit seconds (after the year 5138).

What is the Year 2038 problem?

Systems that count seconds in a signed 32-bit integer cannot represent the second after 2038-01-19T03:14:07Z. This tool converts such times correctly and warns that older systems may not handle them.

Can I use times before 1970?

Yes. Enter a negative value (for example -1 is 1969-12-31T23:59:59Z). Negative values with decimals are rounded in the right direction.

What about daylight saving time?

Times are calculated with IANA time zone rules. A time skipped when daylight saving time starts is flagged, and for a time that occurs twice when it ends you can choose which one to use.

Notes & limitations

  • What you enter is processed only on this page and is not sent to YUCTS servers.
  • The supported range is that of JavaScript Date: ±8.64×10¹⁵ milliseconds (roughly 271821 BC to AD 275760). Sub-millisecond digits are only used for display and unit conversion.
  • Unix time does not count leap seconds, so a leap second (23:59:60) cannot be represented.
  • Time zone rules come from the IANA time zone database built into your browser, so results for historic or future dates can differ between browser versions.

Data sources