Unix Timestamp Converter
Convert between Unix timestamps and readable dates in any time zone. Seconds or milliseconds are detected for you — and nothing you type leaves your browser.
Also available as a desktop app for Windows.
About this tool
A Unix timestamp is a single number: the count of seconds since 1 January 1970 at 00:00 UTC. It is unambiguous, it sorts correctly, and it carries no time zone — which is exactly why every log line, API response and database row is full of them, and exactly why reading one by eye is hopeless.
This tool converts in both directions. Paste a timestamp and you get the instant it refers to — in UTC, in your own time zone, and in a short list of others. Or pick a date and a zone and get the number back. Seconds and milliseconds are told apart automatically, so you never have to count digits.
Everything runs locally in your browser. No timestamp you enter is sent anywhere, and nothing is logged.
Frequently asked questions
- How do I know whether my timestamp is in seconds or milliseconds?
- This tool detects it. Anything below 100,000,000,000 (1e11) is read as seconds, and anything at or above it as milliseconds — which covers every realistic value: 1e11 seconds is the year 5138, while 1e11 milliseconds is 1973. You can also pin the unit yourself when your data is unusual.
- Why does the same timestamp show a different date in different time zones?
- Because a timestamp is one instant, and a time zone is only a way of writing that instant down. 1700000000 is a single moment in time; it reads 22:13 in London and 06:13 the next morning in Shanghai. The instant never moves — the wall-clock reading does.
- Does it handle daylight saving time?
- Yes. Each offset shown is the real one for that specific instant, summer time included. A handful of wall-clock times never happen on their day — the hour a spring-forward jumps over — and the date-to-timestamp side tells you when you have picked one of them.
- What is the largest timestamp it accepts?
- The range a browser date can represent: roughly ±100,000,000 days from 1 January 1970, which is about ±273,000 years. Past that a value is not a date any more, so the tool says so rather than printing “Invalid Date”.
- Is 1 January 1970 a special date?
- Only by convention. Unix was written at Bell Labs in 1969–70 and its authors needed a round starting point, so they took midnight UTC at the beginning of 1970. Timestamps before it are simply negative numbers.
- Can I use it offline?
- Yes — no server is involved. The conversion is plain arithmetic on your own device, so the page keeps working with no connection at all.
Related tools
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