Unix Timestamp Converter

How it works

1. Paste a Unix timestamp in seconds (10 digits) or milliseconds (13 digits). The tool detects which one it is by magnitude.
2. Or paste a date instead: ISO 8601 such as 2026-09-09T12:00:00Z, or any format your browser's Date parser understands. The word now gives the current time.
3. Press Convert. You get the value as seconds and milliseconds, as an ISO 8601 string, as UTC and in your local time zone with its offset.
4. Copy the representation you need for your log query, database record or API call.

Frequently asked questions

What is a Unix timestamp?

The number of seconds elapsed since 1970-01-01 00:00:00 UTC, the Unix epoch, ignoring leap seconds. Many systems use milliseconds instead (JavaScript, Java), and some use microseconds or nanoseconds. Seconds and milliseconds are recognised automatically here.

Which time zone is local time?

The time zone configured in your operating system, as reported by the browser. The UTC and ISO 8601 outputs do not depend on it, so they are safe to share with colleagues in other regions.

What happens in 2038?

Systems that store timestamps as signed 32-bit integers overflow on 2038-01-19 at 03:14:07 UTC. This converter uses 64-bit floating point through the browser's Date object, which handles dates hundreds of thousands of years in either direction.

Why is my date parsed to a different day than I expected?

A date without a time zone, such as 2026-09-09, is treated as UTC by the ISO parser, while 2026-09-09 12:00 without a Z or offset is treated as local time. Always include Z or an explicit offset like +09:00 to avoid ambiguity.

Is the value sent to a server?

No. Conversion uses the browser's built-in Date object on your device. Nothing is uploaded.