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

A Unix timestamp counts seconds since 1 January 1970 UTC. Logs, APIs and databases love it; humans do not. Timestamp converter translates.

Steps

1. Paste a Unix timestamp (1700000000), an ISO date (2026-03-14T09:30:00Z) or the word now.
2. Optionally enter a time zone name such as Asia/Kolkata or America/New_York.
3. Read the result in Unix seconds, milliseconds, ISO 8601 and the readable formats.

Seconds or milliseconds?

A 10-digit number is seconds; a 13-digit number is milliseconds. The tool guesses by size: very large values are treated as milliseconds. JavaScript uses milliseconds, while many servers use seconds. A date in 1970 usually means a seconds value was read as milliseconds.

Time zones

Timestamps have no time zone: they are one moment worldwide. The zone only changes how that moment is written. India is UTC+5:30, so 2026-03-14T09:30:00Z is 15:00 in Kolkata.

Tips

• JWT tokens use exp and iat in seconds; see JWT explained.
• UUID v7 contains a millisecond timestamp in its first bits; see UUID v4 vs v7.
• Use ISO 8601 with Z or an offset whenever you store dates, to avoid ambiguity.

Errors

If the tool cannot understand the input it suggests the accepted formats. Dates like 03/04/2026 are ambiguous (March or April?), so use ISO format.