DEVELOPER TOOLS · 2026

Unix Timestamps Explained: A Quick Reference for Developers

If you've ever seen a date stored as a number like 1758000000 in a database, log file, or API response, that's a Unix timestamp — and understanding it takes about two minutes:

1. What it counts — the number of seconds that have passed since January 1, 1970, 00:00:00 UTC (called the "Unix Epoch"). That specific starting point was chosen somewhat arbitrarily by early Unix developers and has just stuck as the universal standard since.
2. Seconds vs milliseconds — most systems (and Unix itself) use seconds, giving a 10-digit number today; JavaScript's Date.now() and many web APIs instead use milliseconds, giving a 13-digit number. Mixing the two up is one of the most common timestamp bugs.
3. Why developers use it — it's a single plain number, so it's easy to store, compare ("is this timestamp bigger than that one?"), and do date math with, without worrying about timezones, daylight saving, or calendar formatting until you actually need to display it.
4. Timezone-free by design — a Unix timestamp itself has no timezone; it's always relative to UTC. The timezone only comes into play when you convert it to a human-readable date.

Paste any timestamp into our free Unix Timestamp Converter to instantly see it as a readable date (it auto-detects seconds vs milliseconds), or convert a date the other way into a timestamp — all computed locally in your browser.

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