What is Unix Time?
The Unix Epoch (or Unix time) is a system for describing a point in time. It is defined as the number of seconds that have elapsed since 00:00:00 UTC on January 1, 1970 (minus leap seconds).
Why do we use it?
Standardizing time as a single integer makes it incredibly efficient for computers to store, index, and calculate durations. Whether it's a database record, a file modification time, or an API response, Unix time is the backbone of digital scheduling.
Seconds vs. Milliseconds
While the official Unix standard uses seconds, many modern systems (especially JavaScript and Java) operate in milliseconds.
- Seconds (10 digits): Standard for POSIX systems and many APIs.
- Milliseconds (13 digits): Standard for browser-based JavaScript (
Date.now()).
This tool automatically detects whether you've entered seconds or milliseconds based on the string length, ensuring accurate conversion regardless of the source.