Timestamp converter
Unix time ↔ date
Input
Result
Everything is calculated in your browser. The dates you type are never sent to a server.
How to use
Converts between a Unix timestamp (seconds or milliseconds since 1 January 1970) and a readable date. Paste a number and you get this device's time, UTC and ISO 8601; enter a date and you get the timestamp. Nothing is uploaded.
When to use it
- Reading times stored as numbers in logs or a database.
- Finding out when a value like 1730000000 from an API actually is.
- Producing a timestamp for a specific date while developing or testing.
How to use it
- Paste the number into the timestamp box.
- The unit is detected from the digit count — ten for seconds, thirteen for milliseconds. Override it when needed.
- Going the other way, enter a date and time; there is a Now button too.
- Copy whichever of the three notations you need.
Good to know
- When the unit was guessed from the digits, the screen says so. Ambiguous lengths such as eleven or twelve digits need a manual choice.
- Converting to seconds truncates — anything below a second is dropped.
- The supported range runs from year 1 to year 9999; outside it, you are told.
- Decimals and exponent notation (1.7e9) are rejected, while commas, underscores and spaces are stripped.
- An impossible date such as 30 February is reported as invalid rather than quietly shifted.
Frequently asked questions
How do I know if it is seconds or milliseconds?
By the digit count. Between September 2001 and 2286, seconds have ten digits and milliseconds thirteen, which separates almost every real value. The guess is stated on screen so you can override it.
Why 1970?
Unix started counting from that moment and the convention spread. Logs, databases and APIs still use it when a time has to fit into a single number.
What is ISO 8601?
The international notation, written like 2026-10-29T12:34:56Z, where the trailing Z means UTC. Programs exchange times in this form because it leaves no room for misreading.
What about time zones?
A timestamp has no time zone — the number is the same everywhere. That is why this device's local time and UTC are shown side by side. Going from a date to a timestamp, the value you type is read in this device's zone.