What is a Unix timestamp?
A Unix timestamp (or “epoch time”) is the number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970. It’s a simple, timezone-free way for computers to store a moment in time.
FAQ
Seconds or milliseconds? Unix time is usually in seconds, but JavaScript and many APIs use milliseconds (1000× larger). Use the unit switch if your number looks 1000× off.
Is my data stored? No — everything runs in your browser.