A Unix timestamp, also called epoch time, is the number of seconds elapsed since January 1, 1970 at 00:00:00 UTC. It is widely used in programming, databases, APIs, and log files as a universal, timezone-independent way to represent a single point in time as one plain number.
The live counter at the top always shows the current Unix timestamp, updating every second, alongside the equivalent UTC date and time. To convert a timestamp you already have into a readable date, enter it under UNIX → DATE and click Convert. To go the other way, pick a date and time under DATE → UNIX and click Convert to get its Unix timestamp.
Storing time as a single integer rather than a formatted date string avoids a lot of the headaches that come with time zones, date formats, and daylight saving time. Two systems anywhere in the world can compare, sort, or do math on timestamps directly, since a Unix timestamp always represents the same instant regardless of where it's read. That's why it shows up constantly in databases, APIs, log files, and programming languages as the default way to record "when" something happened.
A few details trip people up when working with epoch time: whether it's counted in seconds or milliseconds, whether it carries any time zone information (it doesn't), and how far into the future it can represent on older systems. The FAQ below covers the details most developers and users run into.
If you need to work out the gap between two dates instead of converting a timestamp, the date difference calculator covers that directly.
It originated in early Unix operating systems in the 1970s as a simple, timezone-independent way to store time — just a single integer representing seconds since a fixed reference point (the "epoch").
On 32-bit systems, Unix time is stored as a signed 32-bit integer, which overflows on January 19, 2038. Modern 64-bit systems are not affected.
The standard Unix timestamp counts seconds, but many programming languages and APIs, including JavaScript's Date.now(), return milliseconds instead. Divide by 1000 to convert milliseconds to a standard Unix timestamp.
No — a Unix timestamp is always relative to UTC. It represents the same instant everywhere in the world; local time is only applied when you convert it to a readable date.
Use the DATE → UNIX section: enter the date and time you want, click Convert, and the calculator returns the equivalent Unix timestamp based on your browser's local time zone.
It's widely used in programming, databases, APIs and log files because it's a compact, unambiguous way to store and compare points in time without worrying about time zones or date formatting.