How to convert a Unix timestamp to a date (and back)

Converting a Unix timestamp means turning an epoch number into a human-readable date - or the reverse. A two-way converter helps when you are reading API payloads, checking JWT expiry, or building seed data with known instants.

Convert with Jigglify (30 seconds)

1. Open the timestamp converter.
2. Choose Timestamp to Date to paste Unix seconds or milliseconds (or an ISO-like string).
3. Or choose Date to Timestamp, set the calendar and time, then pick Local or UTC.
4. Copy Unix seconds, milliseconds, ISO, UTC, or local rows from the results.

Timestamp to date

Paste values like 1710000000 (seconds) or 1710000000000 (milliseconds). If the resulting year looks wildly wrong, you almost certainly mixed units - see seconds vs milliseconds.

Date to timestamp

Pick a date and time, then decide whether those fields are Local (your browser timezone) or UTC. The same digits on the clock produce different epoch values depending on that choice. Use UTC when documenting an absolute instant for APIs; use local when matching a user's screen.

JWT and API gotchas

• JWT exp / iat are usually seconds.
• JavaScript Date.now() returns milliseconds.
• Prefer ISO 8601 when pasting date strings across browsers.

Convert Unix time and dates free - seconds, milliseconds, UTC, and local.
Open the free timestamp converter →

Related: What is a Unix timestamp? · Unix seconds vs milliseconds