Unix timestamp converter
Seconds since 1970-01-01 UTC. Milliseconds accepted if the number is 13 digits.
How to use the Unix timestamp converter
What does the Unix timestamp converter do?
Convert Unix epoch seconds to local time and ISO 8601, and back; It applies this page-specific rule: unix time is the number of seconds since 00:00:00 UTC on 1 January 1970, not counting leap seconds the way civil clocks do.
Which inputs does this converter use?
To convert unix epoch seconds to local time and iso 8601, and back, enter Unix (seconds or ms), ISO 8601; keep every value in the same example; select Now when the values are ready; Start with a familiar case covered by this rule - A 10-digit value is treated as seconds - so the expected result can confirm the settings.
How should the converter result be read?
For a result intended to convert unix epoch seconds to local time and iso 8601, and back, a 10-digit value is treated as seconds; read iso 8601 together with the original unix (seconds or ms) rather than as an isolated answer, and confirm that its units or structure match the intended use.
Seconds or milliseconds?
When the goal is to convert unix epoch seconds to local time and iso 8601, and back, 10-digit values are seconds.
Leap seconds?
When using the page to convert unix epoch seconds to local time and iso 8601, and back, unix time as used here follows typical Date implementations, not a leap-second table.
Limits and accuracy
When using this converter to convert unix epoch seconds to local time and iso 8601, and back, the line under the fields is your browser’s local timezone string; check the displayed date, time zone, and daylight-saving status before relying on the result for an important appointment; keep unix (seconds or ms) until the output has been checked in its intended destination.
How this works
Unix time is the number of seconds since 00:00:00 UTC on 1 January 1970, not counting leap seconds the way civil clocks do. Logs, APIs and databases store it because it is a single number.
A 10-digit value is treated as seconds. A 13-digit value is treated as milliseconds (JavaScript’s Date.now() style). The ISO 8601 box is always UTC with a trailing Z.
The line under the fields is your browser’s local timezone string. That is why two people can paste the same epoch and read different clock times.
Frequently asked questions
Seconds or milliseconds?
10-digit values are seconds. 13-digit are milliseconds.
Leap seconds?
Unix time as used here follows typical Date implementations, not a leap-second table.
Can I convert a date only?
Type an ISO string such as 2026-08-25T12:00:00Z and leave the field.