About this tool
Why it exists.
Unix time counts the seconds since 1 January 1970 at 00:00 UTC, ignoring leap seconds. Logs, APIs and databases use it constantly, but humans do not read 1735689600 very well. This converter shows the same moment in local time, UTC and ISO 8601.
Paste a number and the tool detects whether it is in seconds, milliseconds, microseconds or nanoseconds by magnitude. The reverse direction converts a date and time into epoch seconds and milliseconds, and flags invalid calendar dates rather than silently rolling them over.
How to use it.
- Paste an epoch value or use the current time.
- Read the local, UTC and ISO representations.
- Use the date panel to convert a human date back to epoch values.
Good questions.
Is a Unix timestamp in seconds or milliseconds?
Classic Unix time is in seconds. JavaScript's Date.now() and many APIs use milliseconds. A 10-digit number is usually seconds, while 13 digits is usually milliseconds. This tool detects common magnitudes, but you can still misread a timestamp near the boundary.
Why does my converted date look one day off?
Time zones. An epoch value is a single moment in time; its local calendar date depends on the offset of the device viewing it. Compare the UTC value when checking a deadline or server log.