Timestamp Converter

How it works

A Unix timestamp counts the seconds since 1 January 1970 at 00:00:00 UTC. Because it carries no time zone, it is the format of choice for logs, databases, and APIs, and it is why the same instant reads differently on two machines set to different zones.

Paste a timestamp and you get the ISO 8601 string, the UTC form, and the time in your own time zone, along with the value in both seconds and milliseconds. Paste a readable date and the conversion runs the other way.

Units can be detected automatically or forced. Automatic detection reads any value of eleven digits or more as milliseconds, which correctly separates a JavaScript Date.now() value from a Unix timestamp in seconds; set the unit explicitly when you are working with dates far from the present.

Frequently asked questions

Is the timestamp in seconds or milliseconds?

Ten digits is seconds, as in a Unix timestamp from a database or a JWT exp claim. Thirteen digits is milliseconds, as returned by JavaScript's Date.now(). Values of eleven digits or more are read as milliseconds here.

What time zone does a Unix timestamp use?

None. It is an absolute count of seconds since the epoch in UTC. A time zone only enters when you display it, which is why this tool shows the UTC form and your local form side by side.

Which date formats can I paste in?

Anything the browser's Date parser accepts, which reliably covers ISO 8601 such as 2026-08-23T14:30:00Z. Other formats vary between browsers, so ISO is the safest input.

What is the year 2038 problem?

A timestamp stored in a signed 32-bit integer overflows on 19 January 2038. This converter uses JavaScript numbers rather than 32-bit integers, so dates past 2038 convert correctly.

Can it convert a negative timestamp?

Yes. Negative values are instants before 1970, so -86400 is 31 December 1969 at 00:00:00 UTC.