Unix Timestamp Converter

Converts a Unix timestamp (the number of seconds since January 1, 1970, 00:00:00 UTC) into a readable date shown in both UTC and your browser's local timezone, and converts a date back into its Unix timestamp — both directions in the same tool.

Paste a timestamp into the input box to see it as a date, or use the date picker to get its timestamp; click the "Now" button to instantly fill in the current moment as both a timestamp and a readable date.

The timestamp `1704067200` converts to `2024-01-01T00:00:00Z` in UTC. Converting that same date back produces `1704067200` again, since the two operations are exact inverses of each other.

The classic Unix timestamp counts seconds, but many JavaScript APIs (like `Date.now()`) return milliseconds instead — a millisecond timestamp has three extra trailing digits compared to a seconds timestamp for the same moment, which is a common source of thousand-times-off date bugs.

Alongside the human-readable date, the tool also shows the ISO 8601 format (`YYYY-MM-DDTHH:mm:ssZ`), the standard, unambiguous, sortable date format used in APIs, log files, and databases.

This tool works with standard Unix time and does not account for leap seconds, since Unix time itself ignores them by design — for date ranges before 1970, it produces negative timestamp values rather than an error.

Conversion runs entirely in your browser via client-side JavaScript; the timestamps and dates you enter are never uploaded to a server or stored.