Unix Timestamp Converter

Unix time counts the seconds that have passed since 00:00:00 UTC on 1 January 1970, a moment known as the epoch. Systems, databases and APIs store it because it is a single number that means the same instant everywhere. This converter turns a timestamp into a readable date in UTC and in your own time zone, and turns a date back into a timestamp.

It also shows the current Unix time, updating every second.

Different systems count with different precision. Classic Unix tools and many databases use seconds, giving a 10-digit number today (1700000000 is 14 November 2023). JavaScript, Java and many web APIs use milliseconds, a 13-digit number. Some systems store microseconds (16 digits) or nanoseconds (19 digits).

When the unit is set to Auto-detect, the converter guesses it from the size of the number: below about 100 billion it is seconds, up to 100 trillion it is milliseconds, and so on. If the date looks wildly wrong, pick the unit manually.

A Unix timestamp has no time zone: it identifies one instant. Time zones only matter when you display it. The converter shows the same instant in UTC and in the time zone your browser reports, along with the ISO 8601 form (for example 2023-11-14T22:13:20.000Z), which is the safest format for exchanging dates between systems because it is unambiguous and sorts correctly as text.

When converting a date to a timestamp, make sure you choose the right interpretation. A calendar date such as 2026-03-08 02:30 means different instants in different regions, and some local times do not exist or occur twice around daylight-saving changes. For logs and APIs, work in UTC where you can.

Older systems store Unix time as a signed 32-bit integer, which can only count up to 2,147,483,647 seconds. That limit is reached at 03:14:07 UTC on 19 January 2038, after which such a value overflows. Modern systems use 64-bit values, which last for billions of years, but embedded devices and legacy databases may still be affected.

Unix time also ignores leap seconds: each day is treated as exactly 86,400 seconds. That is fine for almost every purpose but matters for precise astronomical or scientific timing. Finally, a timestamp read as milliseconds when it is really seconds lands in January 1970, and the reverse lands tens of thousands of years in the future. Those two symptoms usually mean the wrong unit was assumed.