Unix Timestamp ⇄ Date & Time
ConversionEverything runs locally in your browser — nothing is uploaded
The bar at the top shows the current timestamp, live — click it to drop it into the box below. Under that, one panel per direction: a timestamp into a readable date, or a moment into a timestamp, either picked from the native calendar or pasted as text. Seconds and milliseconds are told apart by length and can be pinned manually. The zone list covers the two dozen zones people actually use, and offsets are taken at the instant being converted, so daylight saving and countries that have changed their rules are both handled. Every result row copies on its own — no select-all-then-trim.
Features
- Live current timestamp (seconds and milliseconds side by side), pausable and clickable to fill the input
- One panel per direction: timestamp → date-time, and date-time → timestamp
- Pick a date-time with the native calendar, or paste text such as 2026-09-18 15:30:45
- Seconds and milliseconds detected automatically, or set by hand
- Twenty common time zones, including half-hour offsets such as India +05:30 and Australia +10:30
- Offsets are taken at the instant being converted, so DST and historical rule changes never shift a result by an hour
- Times skipped by DST raise an error, times that happen twice list both — nothing is silently nudged
- Each result row shows seconds, milliseconds, the selected zone, UTC, ISO 8601 and RFC 2822, and copies on its own
- Batch mode: one entry per line, timestamps and date-times mixed freely, and one bad line does not spoil the rest
- Batch output copies as TSV or downloads as CSV
How to use
- Want the current timestamp? Click the number at the top — it drops into the input
- Timestamp to date: paste it into the first panel and set the unit and zone
- Date to timestamp: pick one with the calendar, or paste the text
- Click Copy on any row to take just that value
- Converting a lot at once? Switch to Batch and paste one entry per line
FAQ
- How are time zones computed, and are they right?
- They come from the browser’s built-in IANA time zone database, so daylight saving start and end dates — and countries that changed their rules, such as Moscow going to permanent UTC+4 in 2011 and back to UTC+3 in 2014 — are resolved for the instant being converted rather than looked up from a fixed offset table. The list offers twenty common zones rather than all four hundred, because a long tail of obscure entries only makes the right one harder to find.
- What if I do not know which zone the data is in?
- Convert in UTC. Picking the wrong zone shifts every result by whole hours, and the shift is invisible — you still get a perfectly well-formed date. When you are unsure which zone a server log was written in, convert in UTC and apply the offset yourself rather than guessing at a zone that is probably right.
- What happens during a daylight saving change?
- On the day DST starts, some clock times do not exist in that zone (02:30 on 2026-03-08 in New York, for instance). The tool reports that plainly and names the skipped span rather than quietly nudging the time to 01:30 or 03:30 — a nudged timestamp looks normal but is an hour out. On the day DST ends, some clock times happen twice (01:30 on 2026-11-01 in New York), and both timestamps are listed, with the earlier one used by default.
- Why was my date format rejected?
- Only a fixed set of formats is accepted (2026-09-18, 2026-09-18 15:30, 2026-09-18T15:30:45), because JavaScript’s new Date(string) is parsed differently across engines — the same input can give different dates and never raises an error. Anything ambiguous, such as 09/18/2026, is refused rather than guessed at. Impossible dates such as 30 February are rejected too, never rolled over.
- What is the year 2038 problem?
- Systems that store seconds in a signed 32-bit integer overflow on 2038-01-19 03:14:07 UTC. This tool works in milliseconds internally and covers roughly ±273,000 years, so dates past 2038 convert fine.
- Why does a 19-digit number report out of range?
- A 19-digit number is far more likely to be a snowflake ID or a database key than a timestamp — millisecond timestamps currently have 13 digits. Use the number base converter for those.
- Is anything uploaded?
- No. Every conversion runs in your browser’s memory, the page makes no network requests, and it keeps working offline.
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