Unix Timestamp Converter

Convert a Unix timestamp (in seconds or milliseconds) into a local date, UTC string, and ISO 8601 format — or pick a date and time to get its timestamp back. All calculations happen locally in your browser.

Developer Tools Runs entirely in your browser

All conversions happen on your device — no data is sent to any server.

Timestamp → Date

Date → Timestamp

What this tool does

Converts between a Unix timestamp — seconds or milliseconds since the start of 1970 — and a readable date, in both directions.

When to use it

A log or database storing dates as numbers that you want to read.
Working out a token's expiry from a numeric field.
Generating a timestamp to put into a request or a test.
Debugging a date discrepancy between two systems.

How to use it

Number to date: enter the timestamp, choose the "Unit" as "Seconds" or "Milliseconds", and click "Convert to date" — or press "Now" for the current moment.
Date to number: pick the date and click "Convert to timestamp" to get the value in both seconds and milliseconds.

A practical example

Input

The timestamp 1700000000 in seconds.

Output

The corresponding date and time, shown in your device's local time.

Limitations

Confusing seconds with milliseconds is the commonest error here: a ten-digit number is usually seconds and a thirteen-digit one milliseconds, and picking the wrong unit gives a date wildly far away.
The display uses your device's local time, which may differ from the UTC your system stores.
A timestamp carries no time-zone information at all; it is an absolute moment, and the display is the local interpretation of it.