Unix Timestamp Converter
Convert between Unix timestamps (seconds or milliseconds) and human-readable dates — UTC or local, any timezone.
Last updated: April 2026 · Runs in your browser · No sign-up
Working with timestamps
Unix timestamps are timezone-free by design — one number, one moment in time, anywhere in the world. Format them for display using the user's timezone; store them as UTC integers. Never store timezoned strings if you can avoid it.
Common formats
- ISO 8601:
2026-04-21T14:30:00Z - Unix seconds:
1776926400 - Unix milliseconds:
1776926400000 - RFC 2822:
Tue, 21 Apr 2026 14:30:00 GMT
Frequently Asked Questions
Seconds or milliseconds — how do I tell?
A 10-digit timestamp (through ~5138 AD) is seconds. A 13-digit timestamp is milliseconds. The tool auto-detects based on length but you can force either.
What's the epoch?
January 1, 1970 00:00:00 UTC — the reference point Unix systems count from. Negative timestamps represent dates before 1970.
Year 2038 problem?
32-bit signed integers overflow on 2038-01-19 03:14:07 UTC. Most modern systems use 64-bit timestamps (good for 292 billion years). Legacy 32-bit systems still in production need migration.
How does it handle timezones?
Timestamps are inherently UTC. The tool shows your local time by default but lets you pick any IANA timezone (Europe/Berlin, America/New_York, Asia/Tokyo etc.).