Turn a Unix timestamp into a date and time, or a date into a timestamp. Everything is calculated on your device.
Convert
Unix time, like 1700000000
Unit
Unix time, like 1700000000
Unit
Time zone
Result
Your result will appear here.
Wednesday, 30 September 2026, 22:15:00
Date and time (America/Argentina/Rio_Gallegos)
ISO 8601 UTC
2026-10-01T01:15:00Z
ISO 8601 local
2026-09-30T22:15:00-03:00
Readable local
Wednesday, 30 September 2026, 10:15:00 pm
Time zone
America/Argentina/Rio_Gallegos (-03:00)
Relative
25 days ago
Unix seconds
1790817300
Unix milliseconds
1790817300000
Read as
Seconds, 10 digits (auto)
How it’s calculated
Seconds since 1970-01-01 00:00:00 UTC = 1,790,817,300
Auto reads up to 11 digits as seconds, 12 to 14 as milliseconds, 15 to 17 as microseconds and more as nanoseconds.
No leap seconds: every day has 86,400 seconds.
Local is your device’s time zone, America/Argentina/Rio_Gallegos.
Relative uses this device’s clock.
1790817300
Unix timestamp (seconds)
Unix milliseconds
1790817300000
ISO 8601 UTC
2026-10-01T01:15:00Z
ISO 8601 local
2026-09-30T22:15:00-03:00
Relative
25 days ago
How it’s calculated
Seconds since 1970-01-01 00:00:00 UTC = 1,790,817,300
No leap seconds: every day has 86,400 seconds.
Local is your device’s time zone, America/Argentina/Rio_Gallegos.
Relative uses this device’s clock.
What it does
The converter turns a Unix timestamp into a date and time, both in UTC and in your device’s time zone, with the time zone’s offset, how long ago or how far ahead it is, and the timestamp in seconds and in milliseconds. It also works the other way: enter a date and time and get its Unix timestamp. The answer updates as you type, and every line has its own Copy button.
How to use it
The page opens with the current time as a timestamp, shown as a date.
Type or paste a timestamp. Leave Unit on Auto, or pick Seconds, Milliseconds, Microseconds or Nanoseconds.
To go the other way, select To timestamp and pick a date and time.
Choose Local for your device’s time zone, or UTC.
Select Copy next to a line for that value alone, or Copy result for all of them.
The converter remembers the direction, the unit and the time zone on this device. The timestamp and the date aren’t kept: each visit starts from now.
How it’s calculated
A Unix timestamp counts the seconds since 00:00:00 UTC on 1 January 1970; a negative one counts back from it. Milliseconds, microseconds and nanoseconds count the same time in thousandths, millionths and billionths of a second. The converter reads the digits as one exact whole number, so even a 19-digit nanosecond timestamp keeps every digit, and the ISO 8601 times show the fraction to the unit you chose.
Unix time has no leap seconds: every day is 86,400 seconds. The local time comes from your browser’s time zone data for your device’s zone. A local date and time is turned back into a timestamp in that zone: a time skipped when the clocks go forward is moved on by the gap, and a time that happens twice when they go back is taken as the earlier one. The result says so when either applies. How long ago or ahead a time is uses this device’s clock.
Good to know
Timestamps can be anything from 00:00:00 UTC on 1 January 0001 to 23:59:59 UTC on 31 December 9999, in up to 32 characters: digits, with an optional minus sign in front. Anything else is marked at the field.
The copied values use a plain hyphen for a minus sign, so they paste straight into code.
Readable local shows the 12-hour clock, such as 10:13:20 pm; the main result and the ISO 8601 times use the 24-hour clock.
For dates before a time zone kept standard time, the time zone data uses the local mean time of its main city, so the offset can have seconds, such as -00:01:15 for London before 1847.
Dates before 1582, when the Gregorian calendar began, follow its rules too, so they can differ from the calendar that was in use at the time.
Privacy
Everything is calculated in your browser, on your device. Nothing you type is uploaded. The timestamp and the date aren’t stored; only your choices for the direction, the unit and the time zone are kept, in this browser’s storage, so the page can show them again.
Frequently asked questions
Is my timestamp in seconds or milliseconds?
Count the digits. For dates from 2001 to 2286, a timestamp in seconds has 10 digits and one in milliseconds, as JavaScript's Date.now() gives, has 13. Auto picks the unit by size: up to 11 digits as seconds, 12 to 14 as milliseconds, 15 to 17 as microseconds and more as nanoseconds. The Read as row shows what it chose. Pick a unit yourself for a value Auto would misread, such as a small millisecond count close to 1970.
Can a Unix timestamp be negative?
Yes. A negative timestamp counts back from 1 January 1970: -1 is 23:59:59 UTC on 31 December 1969, and -86400 is the start of that day. The converter reads any timestamp back to 1 January in the year 1.
What is the year 2038 problem?
Systems that keep Unix time in a signed 32-bit number can count only up to 2,147,483,647, which is 03:14:07 UTC on 19 January 2038. One second later the number wraps round to a negative value, read as a date in December 1901. This converter works with whole numbers of any size, so dates up to the year 9999 convert correctly.
How does daylight saving affect a conversion?
A timestamp is one instant, so it always has one local time. Going from a local date and time to a timestamp is different: when the clocks go forward, the skipped times don't exist, and when they go back, an hour happens twice. In London, 01:30 on 29 March 2026 is read as 02:30, and 01:30 on 25 October 2026 is taken as the first of the two. The result says which rule it used.
Does Unix time count leap seconds?
No. Unix time treats every day as exactly 86,400 seconds, so a leap second such as 23:59:60 UTC on 31 December 2016 has no timestamp of its own, and the leap seconds added since 1972 aren't counted. The converter follows the same rule, so its results match what computers store.