Convert Unix epoch timestamps to human-readable dates and back. Supports seconds and milliseconds, with ISO, UTC, and relative outputs.
A Unix timestamp is a single number that records a precise moment in time as the count of seconds (or milliseconds) elapsed since the Unix epoch — 00:00:00 UTC on 1 January 1970. This converter translates that number into human-readable dates in Local, UTC, ISO 8601, and RFC 2822 formats, and converts any calendar date back into its epoch value, all in one place.
Because a timestamp carries no timezone of its own, it is the cleanest way to store and exchange an instant in time. People use it to:
Everything runs local and in-browser: your timestamps never leave your device, there is no server round-trip, and the tool keeps working offline once the page has loaded.
A Unix timestamp is a single number that represents a moment in time as the count of seconds elapsed since the Unix epoch. Because it carries no timezone, APIs, databases, and logs use it as a compact, unambiguous way to record exactly when something happened.
The Unix epoch is fixed at 00:00:00 UTC on 1 January 1970, the reference point chosen by early Unix system designers. Every Unix timestamp is measured as the number of seconds before or after that exact instant.
Seconds count whole seconds since the epoch, while milliseconds count thousandths of a second, so a millisecond value is 1000 times larger. As a rule of thumb a 10-digit value is in seconds and a 13-digit value is in milliseconds; pick the matching unit so the date lands in the expected year.
The timestamp itself is always anchored to UTC and has no timezone of its own. This converter shows the same instant in both your local timezone and UTC, plus ISO 8601 and RFC 2822, so you can read it however your tooling expects.
Systems that store timestamps in a signed 32-bit integer can only count up to 03:14:07 UTC on 19 January 2038, after which the value overflows and wraps to a negative number. Modern systems avoid this by using 64-bit integers, which extend the usable range far beyond any practical date.
Use the "Date → Timestamp" panel: pick a calendar date and time in your local timezone and the tool returns the equivalent epoch value in both seconds and milliseconds, along with UTC and ISO 8601 forms you can copy.
No. Every conversion happens locally in your browser using JavaScript, so your timestamps and dates never leave your device. Once the page has loaded it also continues to work offline.