Unix Timestamp Converter
Convert between Unix epoch (seconds or milliseconds) and human-readable date / time, in UTC and local.
Two-way converter: Unix epoch on one side (seconds or milliseconds), human date on the other. Both sides update as you type. The current 'now' is one click away if you need a quick timestamp for a log line or a fixture.
UTC
Invalid
Local
Invalid
ISO 8601
Invalid
Relative
Invalid
How to use it
Type a timestamp or a date
Either side accepts input; the other updates live.
Pick seconds vs milliseconds
Auto-detected, but you can toggle if the auto-detection guessed wrong.
Copy what you need
UTC, local, ISO 8601 or raw epoch are all shown.
What is it?
Unix time is a count of seconds (or milliseconds) since the Unix epoch - 1970-01-01T00:00:00 UTC. It's the universal machine-readable timestamp: timezone-free, monotonic (mostly), and trivial to compare. Most databases, log formats and APIs use it under the hood, but humans read it in date-time strings, so a converter is the constant translation between the two.
When to use it
Debugging a log line that reports timestamps in raw epoch. Building a test fixture from a known date. Converting between an API response's 'created_at: 1700000000' and what that date actually was. Generating a future timestamp for a 'scheduled at' field.
Common mistakes
Mixing up seconds and milliseconds - 1700000000 is November 2023, but 1700000000000 is the same instant. Forgetting that the displayed local time depends on the viewer's timezone, so a screenshot of '14:00 EST' on your machine reads differently on someone else's. And treating epoch as if it accounted for leap seconds - it doesn't.
FAQ
- Seconds or milliseconds?
- Unix time is traditionally seconds since 1970-01-01T00:00:00Z, but JavaScript's Date uses milliseconds. We auto-detect from the magnitude of the number, and you can toggle explicitly.
- What's the year 2038 problem?
- Signed 32-bit Unix timestamps overflow on 2038-01-19T03:14:07Z. Most modern systems use 64-bit timestamps, so this tool handles dates far beyond that without trouble.