Unix timestamp
Convert to a date and back
No database: AIMRAN doesn't store your files, text or results
What is Unix timestamp?
A Unix timestamp is the number of seconds that have passed since January 1, 1970. Computers use it to store dates, but it's unreadable for people. This tool turns it into a normal date and back.
You can see the date in any time zone in the world, in ISO 8601 format and as relative time (“3 days ago”).
How to use it
- Paste a timestamp into “Timestamp to date” or click “Now”.
- Leave the unit on “Auto” or choose seconds, milliseconds, microseconds or nanoseconds.
- Choose the time zone under “Show in”.
- For the reverse calculation, enter the date and time under “Date to timestamp”.
- Copy the seconds, milliseconds or the ISO 8601 date.
Advantages
- Detects automatically whether the timestamp is in s, ms, µs or ns.
- All IANA time zones, with their UTC offset.
- ISO 8601 format, UTC and relative time.
- Free, no sign-up and no ads.
Technical details
The Unix timestamp (epoch) counts seconds since 1970-01-01T00:00:00Z without leap seconds. The unit is detected by the number of digits: up to 11 is read as seconds, up to 14 as milliseconds, up to 17 as microseconds and beyond that as nanoseconds; negative values are also accepted for dates before 1970. Time zones come from the IANA database available through Intl, with format and offset calculated for that specific instant, so daylight saving changes are respected. To convert a wall-clock date in a zone to a timestamp, two offset-correction passes are made. ISO 8601 output includes the zone offset or Z for UTC.
Frequently asked questions
What is a Unix timestamp?
The number of seconds elapsed since January 1, 1970 at 00:00 UTC. For example, 1735689600 corresponds to January 1, 2025 at midnight UTC.
How do I know if a timestamp is in seconds or milliseconds?
By its length: current ones have 10 digits in seconds and 13 in milliseconds. The tool detects it automatically in “Auto” mode.
How do I get the current timestamp?
Click “Now” and you'll see the current timestamp in seconds and milliseconds, ready to copy.
Does the timestamp depend on the time zone?
No. The timestamp is always the same instant worldwide; what changes is how the date is displayed in each time zone.
What is the year 2038 problem?
Systems that store the timestamp in a signed 32-bit integer overflow on January 19, 2038. 64-bit systems don't have that limit.
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