Unix Timestamp Converter
Epoch seconds, milliseconds and readable dates.
- Runs in your browser
- Free, no signup
Unix time is the number of seconds since 1 January 1970 at 00:00 UTC, and it is what most APIs and databases store. Convert a timestamp into a readable date, or a date into a timestamp. All of it is calculated here in the page.
Right now Live
- Unix seconds
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- Unix milliseconds
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- Your time
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- UTC
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Ten digits is seconds, thirteen is milliseconds. The length is detected as you type, so this only matters when it is ambiguous.
Readable date
- Date
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- Time
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- Date and time
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- ISO 8601
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- UTC
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- Selected timezone
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- Relative
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- Weekday
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YYYY-MM-DD HH:MM:SS. An ISO 8601 offset
(2026-10-09T12:30:00+05:30) is honoured and the
timezone below is then ignored.
Unix time
- Seconds
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- Milliseconds
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- Read back as UTC
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Every conversion runs in this browser, using your device's own clock and timezone. Nothing is sent anywhere.
A Unix timestamp is a single number: the seconds elapsed since 1 January 1970 at 00:00 UTC, ignoring leap seconds. It is what nearly every database, log line and API stores and what almost nobody can read at a glance. The number in a log entry means nothing until it is a date, which is what this page is for.
It converts in both directions and in any timezone, using the browser's own date and timezone handling rather than a copy of the timezone database. That means the times shown are the times your device actually observes — including whatever daylight-saving rule applies where you are — and it means the page keeps working with no request per keystroke.
How to use this tool
- Paste a timestamp and the unit is detected from its length: ten digits is seconds, thirteen is milliseconds. Change the unit yourself if you have an unusual value.
- Choose the timezone to read it in. The date, the time, ISO 8601, UTC and the relative time all update together.
- For the other direction, open Date to Timestamp, type a date, and pick the timezone that date is written in.
Seconds or milliseconds
Unix time is defined in seconds, but a great many systems store milliseconds — JavaScript's `Date.now()` returns milliseconds, Java uses them, and so do most event streams. The two are easy to tell apart by length: ten digits is seconds and stays in this century until 2286, while thirteen is milliseconds and covers the same range with three extra digits.
Getting it wrong by a factor of a thousand is the classic bug, and the failure is loud rather than subtle — a seconds value read as milliseconds lands in January 1970, and a milliseconds value read as seconds lands in the year 58 000. If you are unsure, look at the magnitude rather than the digit count; a plausible-looking date is the strongest signal.
UTC, local time and ISO 8601
A timestamp is an instant, and an instant has no timezone. The timezone appears when you write it down, which is why the same number is five and a half hours later in a log written in India than in one written in London. This page shows both: UTC, and whichever zone you selected.
ISO 8601 is the written form that survives being copied between systems: `2026-10-09T12:30:00Z`, or with a real offset such as `2026-10-09T18:00:00+05:30`. The `Z` means UTC and the offset means the reading is in a named zone, and both are shown here because both are what a downstream tool will want.
Dates before 1970
Nothing about Unix time requires it to be positive. A negative timestamp counts backwards from the epoch, so `-86400` is 31 December 1969. Timestamps before the epoch are entirely legitimate and turn up in birth dates, historical data and the occasional misconfigured clock.
This page represents them directly rather than refusing them, and it reports the range limit honestly: past about ±8.64 × 10¹⁵ milliseconds a date cannot be represented at all, and a value beyond that is refused rather than printed as an invalid date.
Frequently asked questions
What is a Unix timestamp?
The number of seconds since 1 January 1970 at 00:00 UTC, not counting leap seconds. It is a single number, it has no timezone, and it grows by one every second everywhere in the world at once.
How do I tell seconds from milliseconds?
By length and magnitude. Ten digits is seconds and reaches this decade; thirteen is milliseconds. A seconds value treated as milliseconds lands in 1970, and a milliseconds value treated as seconds lands tens of thousands of years in the future.
Why is the date different from what I expected?
Almost always the timezone. A timestamp is the same instant everywhere, but it is a different wall-clock reading in each zone. Check which zone is selected — UTC and your local zone can be on different days.
Does this handle dates before 1970?
Yes. A negative timestamp counts backwards from the epoch, and these are converted normally.
Is the timestamp sent anywhere?
No. The conversion uses your browser's own date and timezone support, so nothing leaves the page and the live clock is your device's clock rather than a server's.