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How to convert a Unix timestamp

Logs, databases, and API responses love Unix timestamps — bare numbers like 1700000000 that mean nothing to a human until you convert them. This guide explains what the number is, the one mistake that makes dates come out wrong, and how to convert either direction with the free Timestamp Converter.

The fastest way

Paste the number into the Timestamp Converter to get a readable date, or enter a date to get the timestamp back. Read on for the gotcha that catches almost everyone.

What the number means

A Unix timestamp counts the seconds since midnight UTC on 1 January 1970 — the "Unix epoch." It's a compact, time-zone-free way to pin down an exact instant, which is why systems store it instead of a formatted string.

The seconds-vs-milliseconds trap

This is behind nearly every "my date is wrong" problem:

If a 13-digit value reads as a date in 1970, it's milliseconds being read as seconds. Check the digit count first and you'll avoid the mistake.

Time zones

The timestamp itself is always UTC — it carries no zone. The zone only matters when you display it: the same instant is a different wall-clock time in Tokyo than in New York. If you need to line up a time across zones, the Time Zone Converter handles that side.

A note on privacy

There's nothing to upload here — the Timestamp Converter is pure arithmetic done in your browser.

Open the Timestamp Converter →

Common questions

What is a Unix timestamp?

It's the number of seconds that have elapsed since midnight UTC on 1 January 1970, called the Unix epoch. So 1700000000 is a specific moment in November 2023. It's a compact, time-zone-free way for systems to store an instant in time.

Why is my timestamp off by decades or shows 1970?

Almost always the seconds-versus-milliseconds mix-up. Many systems (including JavaScript) store the value in milliseconds, which is 1000× larger. If a 13-digit number reads as a date in 1970, it's milliseconds being read as seconds; a 10-digit number is seconds.

How many digits should the timestamp have?

A timestamp in seconds for a current date is 10 digits. In milliseconds it's 13 digits. A quick glance at the length tells you which unit you have before you convert.

Does a Unix timestamp carry a time zone?

No. The epoch value is always relative to UTC. The time zone only matters when you display it as a human date — the same timestamp shows as different wall-clock times in different zones, but it's the same instant.

Is my data uploaded when I convert?

No. The conversion runs in your browser, so there's nothing to send — it's pure arithmetic on the number you enter.