Convert Unix epoch ↔ human dates across every major time zone
A Unix timestamp is the number of seconds (or milliseconds) since January 1, 1970 UTC — the dominant way computers encode time. Converting to a human-readable date is a daily task when reading logs, debugging APIs, or correlating database rows across services. This converter does both directions and shows the same instant across every major time zone so you can reason about global events quickly.
Unix and most databases use seconds (10 digits). JavaScript Date.now() and most APIs built after 2010 use milliseconds (13 digits). If your timestamp is 10 digits long, use seconds.
Not for this tool — JavaScript uses 64-bit doubles for Date, so we handle timestamps up to year 275,760. Your backend might still have the 32-bit int overflow problem (Jan 19, 2038).
Human-friendly age: '3 hours ago', '2 days from now'. Useful for eyeballing whether a token is expired or a scheduled event is near.
Yes. Each zone's render uses Intl.DateTimeFormat with formatToParts, which computes the correct offset at the target instant — not just the current offset.
Your system clock. If it's wrong, the 'current time' block and 'relative' outputs will be wrong too.
