Unix Timestamp Converter
Turn a Unix timestamp into a readable date in UK time and UTC, or turn a date back into a timestamp. Seconds, milliseconds, microseconds and nanoseconds are detected automatically. Runs in your browser.
Or pick a date and time
Try an example:
Private by design: conversions use your browser’s built-in date and time-zone data. Nothing is uploaded or stored.
How to use the Unix Timestamp Converter
- The live clock at the top shows the current Unix time in seconds and milliseconds. Click either number to copy it.
- Paste a timestamp such as
1791100800into the box. The unit is detected from the number of digits: up to 11 digits is seconds, 12–14 milliseconds, 15–17 microseconds and 18–19 nanoseconds. Choose a unit yourself if you need to. - Or paste a date, such as
2026-10-04 09:00,2026-10-04T09:00:00ZorSun, 04 Oct 2026 08:00:00 GMT, to get its timestamp. Dates without a time zone are read in the zone chosen under “Or pick a date and time”, which is UK time by default. - Open Or pick a date and time to choose a date from a calendar in UK time, UTC or your device’s time zone.
- Read the result: the date in UK time and UTC, ISO 8601 and HTTP formats, the ISO week number, how long ago or how far ahead it is, and the timestamp in all four units. Every line has a Copy button.
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What is a Unix timestamp?
A Unix timestamp (also called epoch time or POSIX time) is the number of seconds since 00:00:00 UTC on 1 January 1970, not counting leap seconds. It’s how most computers, databases and APIs store moments in time, because a single number is easy to sort, compare and store, and it means the same moment everywhere in the world. Time zones and summer time only come in when the number is turned into a date for people to read.
Different systems count in different units. Unix tools, PHP, Python’s time.time() and JWTs use seconds. JavaScript’s Date.now() and Java use milliseconds. Some databases and logging systems use microseconds, and Go and high-precision tracing use nanoseconds. Mixing them up is a common bug: a millisecond value read as seconds lands tens of thousands of years in the future. This converter spots the unit for you and shows all four, using exact whole-number maths so very large nanosecond values don’t lose precision.
UK time, BST and UTC
UK time is GMT (the same as UTC) in winter and British Summer Time (UTC+1) from the last Sunday in March to the last Sunday in October. The converter uses your browser’s official time-zone data, so it labels each date as GMT or BST correctly for any year. Around the clock changes it also warns you about local times that don’t exist (the hour skipped when the clocks go forward) or happen twice (the hour repeated when they go back), which often cause scheduling bugs.
Formats explained
- ISO 8601, such as
2026-10-04T08:00:00.000Z: the international standard and the safest choice for APIs and JSON. TheZmeans UTC. The UK version shows the offset, such as+01:00. - HTTP / RFC 7231, such as
Sun, 04 Oct 2026 08:00:00 GMT: used in HTTP headers likeExpiresandLast-Modified, and in cookies. - ISO week: the week number used in business planning, where weeks start on Monday and week 1 contains the first Thursday of the year.
The Year 2038 problem
Older systems store Unix time as a signed 32-bit number, which runs out at 03:14:07 UTC on 19 January 2038 (timestamp 2147483647). One second later it wraps round to December 1901. Modern systems use 64-bit time and are fine, but embedded devices, old databases and some file formats may not be. The converter tells you when a date is past this limit, so you can check how your systems handle it.
Privacy
All conversions run in your browser using its built-in date and time-zone data. Nothing you type is uploaded or stored.
Frequently asked questions
How do I get the current timestamp in code?
JavaScript: Math.floor(Date.now() / 1000). Python: int(time.time()). PHP: time(). Linux shell: date +%s. SQL varies, for example UNIX_TIMESTAMP() in MySQL.
Does Unix time include leap seconds?
No. Every Unix day is exactly 86,400 seconds, which is why it’s so easy to calculate with.
Why is my timestamp an hour out?
Usually the date was read in the wrong time zone, often UK time versus UTC during British Summer Time. Compare the UK and UTC lines.
Can it handle dates before 1970?
Yes. Earlier dates have negative timestamps, though some systems don’t accept them.
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