Unix Timestamp Converter

Unix timestamps count seconds since 1 January 1970 UTC, and this reads them in both directions: expand a timestamp into a readable date, or pick a date and get its timestamp, with the UTC value and your own local rendering shown side by side. Anyone reading logs, debugging an API that returns epoch values, or setting an expiry in a token spends time doing exactly this conversion. The most common trap is units. Seconds and milliseconds look identical at a glance but differ by a factor of a thousand, which is why a timestamp can land absurdly in 1970 or somewhere in the year 55000 — if a date looks wrong by that much, the units are the reason. A timestamp is always an instant in UTC; the local time shown alongside it depends entirely on your device's timezone setting, so quote the UTC value when sharing.