Timestamp Converter turns Unix timestamps into readable dates and back again. It auto-detects the unit, shows the same instant in UTC, your local time and any time zone with daylight saving applied, lists every common representation (ISO 8601, RFC 3339, RFC 2822, epoch seconds, milliseconds, microseconds and nanoseconds), formats a custom pattern and adds the Star Trek stardate. Everything runs in your browser.
A Unix timestamp (or epoch time) counts the seconds since 1970-01-01T00:00:00 UTC. It is the same instant everywhere on Earth, so it is the natural way to store a moment. The same instant can also be written in smaller or larger units: seconds, milliseconds, microseconds or nanoseconds.
Open the Timestamp → Date tab and type a value. The unit is detected automatically from the number of digits (10 = seconds, 13 = milliseconds, 16 = microseconds, 19 = nanoseconds) and shown as a note below the field. If a value is ambiguous, pick the unit yourself in the Unit dropdown, including Auto-detect. The Now button inserts the current instant, and decimals (a dot or comma) are accepted for sub-second values.
The Date → Timestamp tab does the opposite. Pick a date and time, choose the time zone that the entered value refers to, and every representation updates at once. Time zones are handled correctly across daylight-saving changes, so a wall-clock time is always converted to the right absolute instant.
The All representations panel lists the instant as ISO 8601, RFC 3339, RFC 2822, UTC text, your display time zone, your local time, Unix seconds, milliseconds, microseconds, nanoseconds and the stardate. Use the Copy button on any row for a single value, Copy all for the whole list, or download everything as .txt, .csv or .json.
The Time zones panel shows the same instant in every zone you have selected, with its UTC offset and short label. Zone offsets include daylight saving: a zone currently on summer time is marked with a DST tag. Add any zone from the dropdown and remove one with the × button.
Enter a pattern in the Custom format field to build your own output, in any of the selected time zones. Tokens include YYYY YY MMMM MMM MM M DD D HH H hh h mm m ss s SSS A Z ZZ zzz dddd ddd dd d; every other character is copied literally. The live preview sits right below the field.
The Stardate tab converts between a date and a Star Trek stardate, and the stardate is also shown in the representations list. It uses the widely accepted TNG-era convention: stardate 41000.0 is 1 January 2364, 1000 stardate units span one year, and the day of the year supplies the fraction (leap years included). Round-trip date → stardate → date is exact.
Every conversion runs locally in your browser using the built-in date and time zone APIs. Nothing is uploaded and nothing is stored on a server, which is why the app is marked as green (Local).