Unix Timestamp Converter
Convert Unix timestamps (seconds or ms) to UTC and local time, or any date back to a timestamp.
Quick answer: Convert Unix timestamps (seconds or ms) to UTC and local time, or any date back to a timestamp.
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Frequently asked questions
- How do I convert a Unix timestamp?
- Paste the number, pick seconds or milliseconds, and the UTC and local times appear instantly.
- How do I tell seconds from milliseconds?
- 10-digit numbers are seconds (Unix epoch); 13-digit numbers are milliseconds (the Date.now() format JavaScript uses).
- What is a Unix timestamp?
- The number of seconds (or ms) since 1970-01-01 00:00:00 UTC. It's the lingua franca for timestamps in databases and APIs.
- Why does my local time differ from UTC?
- Local time is your device's timezone — UTC is the absolute reference. Unix timestamps are always UTC under the hood.
- Can I convert ISO dates to Unix?
- Yes — paste a date like `2024-01-01T00:00:00Z` in the second box and we give you both the seconds and millisecond timestamps.
- Are the dates sent anywhere?
- No. Conversion runs entirely in your browser.
- What about the Year 2038 problem?
- 32-bit signed timestamps overflow on 2038-01-19. Modern systems use 64-bit so this tool handles dates well past then.
- Can I convert negative timestamps?
- Yes — they represent dates before 1970. Useful for historical date math.
- Does it handle leap seconds?
- Unix time deliberately ignores leap seconds — every day is exactly 86,400 seconds — so this tool follows the same convention.
- Is this timestamp converter free?
- Yes — free, no signup, no limits.