What does auto unit detection do?
It estimates the unit from the number length and magnitude. Choose the explicit unit when precision is known.
Translate timestamps while debugging events
Unix timestamps appear in logs, queues, analytics exports, cache records, job schedulers, API payloads, JWT claims, and database rows. This converter accepts seconds, milliseconds, microseconds, and nanoseconds, then shows the date as local time, UTC, ISO 8601, relative time, weekday, and copy-ready numeric values.
Auto-detection uses the size of the number to infer the unit, but you can force the unit when a value comes from a system with known precision. The date input works in the other direction when you need a timestamp for tests or manual API calls.
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Useful debugging checks
- Check whether a backend sent seconds while the frontend expected milliseconds.
- Convert JWT exp, iat, and nbf claims to readable times before investigating auth failures.
- Compare local time and UTC when an incident crosses timezones or daylight-saving boundaries.
- Create exact timestamps for test fixtures, scheduled jobs, cache expiry, and API examples.
- Use microsecond or nanosecond inputs from logs while still copying normalized seconds or milliseconds.
Seconds vs milliseconds
The most common timestamp bug is a unit mismatch. Unix timestamps are often seconds in backend systems and JWT claims, while JavaScript Date uses milliseconds. A value that looks far in the future or near January 1970 is often using the wrong unit.
Timestamp converter FAQ
Why show both local time and UTC?
Logs and APIs often store UTC, while people reason in local time. Seeing both prevents timezone mistakes.
Can I convert a date back to a timestamp?
Yes. Use the local date and time input to get seconds and milliseconds for that moment.
