Timestamp Converter
Convert Unix time to a readable date and back, in any timezone — with daylight-saving transitions handled correctly because this uses your browser's own timezone database, not a hand-rolled one.
Right now
{{ nowSeconds }}
Unix time, seconds — updates live.
{{ parseError }}
| ISO 8601 | {{ isoText }} |
| RFC 2822 | {{ rfcText }} |
| In {{ timeZone }} | {{ zonedText }} |
| Custom format | {{ customText }} |
| Unix (seconds) | {{ Math.floor(currentMs / 1000) }} |
| Unix (milliseconds) | {{ currentMs }} |
| Relative | {{ relativeText }} |
Compare across timezones
| {{ row.zone }} | {{ row.formatted }} |
Batch conversion
Paste a list of timestamps or dates — one per line — to convert them all at once.
| Input | In {{ timeZone }} |
|---|---|
| {{ row.input || '(empty)' }} | {{ row.valid ? row.formatted : 'Could not parse' }} |
Every conversion runs in your browser, using its own built-in timezone data. Nothing you enter is uploaded to a server.
Why timezone conversion here isn't hand-rolled
Correct timezone math means knowing every daylight-saving transition, historical offset change, and
political timezone redefinition for every zone on Earth — the IANA time zone database, updated several
times a year. Rather than vendor and maintain a copy of that database, this tool uses your browser's
own built-in Intl support, which already carries this data and keeps it current with
browser updates. This tool is the interface and the batch/comparison layer built on top of that — not
a second, hand-maintained timezone implementation that could quietly drift out of date.
Why the unit is detected automatically
A bare integer carries no unit of its own — 1738368000 could be seconds, milliseconds or something else, and there's nothing about the digits that says which. This tool uses the same convention most systems settle on: seconds-since-epoch is currently 10 digits, milliseconds 13, microseconds 16 — so pasting a timestamp exactly as you have it, without converting it yourself first, works correctly.
Frequently asked questions
How does it know if my number is seconds or milliseconds?
By digit count: 10 digits is read as seconds, 13 as milliseconds, 16 as microseconds — the same convention most systems use, since a bare integer carries no unit of its own. Paste the number as you have it; the unit is detected automatically.
Why trust this tool's timezone handling?
It doesn't implement timezone or daylight-saving rules itself — it asks the browser's own built-in Intl support, which carries the full IANA timezone database and stays current through normal browser updates. That's the same database real operating systems and programming languages use, not a separate copy that could quietly go out of date.
What does the timezone comparison show?
The same instant in time, formatted in several timezones side by side — useful for scheduling something across regions without doing the offset math by hand, especially since a fixed "+5:30" offset silently breaks across a daylight-saving transition in zones that observe it.
Can I convert a whole list of timestamps at once?
Yes — paste one timestamp or date per line into the batch box and every line is converted independently, in order, which is the actual shape of pulling times out of a log file.
Is my data sent anywhere?
No. All parsing and formatting happens in your browser using JavaScript and its native Intl support. Nothing is transmitted to a server.