Unix Timestamp Converter
Turn a Unix (epoch) timestamp in seconds or milliseconds into a date and time in UTC and any time zone, with ISO 8601 and RFC 2822 forms, or a date and time back into a timestamp.
Result…
How it's calculated
Unix time = (date and time in UTC − 1970-01-01 00:00:00 UTC) in seconds Milliseconds = seconds × 1000 UTC = local time − the zone's offset on that date
A Unix timestamp (also called epoch or POSIX time) is the number of seconds since midnight UTC on 1 January 1970, ignoring leap seconds. JavaScript, Java and many web APIs use milliseconds instead, so a 13-digit number is usually milliseconds and a 10-digit one seconds. The same timestamp is the same instant everywhere; only the local clock reading differs by time zone. Systems that store the seconds in a signed 32-bit integer overflow after 2,147,483,647, which is 03:14:07 UTC on 19 January 2038 (the "year 2038 problem"); 64-bit storage avoids it.
Your numbers, step by step
About the Unix Timestamp Converter calculator
This Unix timestamp converter turns epoch time into a readable date and back. Paste a timestamp in seconds or milliseconds (it can tell them apart by size) and see the date and time in UTC, the same moment in any time zone you choose, and the ISO 8601 and RFC 2822 strings that logs, APIs and email headers use. Or enter a date, a 24-hour time and a time zone to get the timestamp in seconds and milliseconds. Developers use it to read log files, debug API responses and set expiry times in tokens and cookies. Time zone offsets, including daylight saving on that date, come from your browser's own time zone database, and the steps show the days since 1970 and the offset used. It also shows how far a timestamp is from the 32-bit limit in January 2038.
How to use it
- Under “Convert”, choose “Timestamp to date” or “Date to timestamp”.
- For a timestamp, enter the “Unix timestamp” and leave “The timestamp is in” on “Detect”, or pick seconds or milliseconds.
- For a date, enter the “Date” and the “Time (24-hour)”, such as 14:30:00.
- Pick the “Time zone” to show the result in, or the zone your date and time are in.
- Read the UTC time, the local time, the ISO 8601 and RFC 2822 forms, and the offset.
Worked example
The timestamp 1700000000 is 19,675 whole days plus 80,000 seconds after 1 January 1970, which is 14 November 2023 at 22:13:20 UTC (ISO 8601: 2023-11-14T22:13:20Z; RFC 2822: Tue, 14 Nov 2023 22:13:20 +0000). In Asia/Karachi (UTC+05:00) that is 03:13:20 on 15 November. The 13-digit value 1700000000000 is the same moment in milliseconds. Going back, 12:00:00 on 27 October 2026 in Europe/London, which is on UTC+00:00 that day, is the timestamp 1793102400.
Updated
Questions people ask
How do I convert a Unix timestamp to a date?
Add that many seconds to 1 January 1970 00:00:00 UTC, then apply your time zone's offset for that date. The calculator does both and shows the days and seconds it counted.
Is my timestamp in seconds or milliseconds?
A current timestamp in seconds has 10 digits and one in milliseconds has 13. JavaScript's Date.now() gives milliseconds, while many databases and Unix tools give seconds.
What is the year 2038 problem?
Systems that keep Unix time in a signed 32-bit integer can count only to 2,147,483,647 seconds, which is 03:14:07 UTC on 19 January 2038. After that the number overflows unless the system uses 64-bit time.
Does a Unix timestamp depend on the time zone?
No. A timestamp is one instant, the same everywhere; only the clock reading differs between zones. A common mistake is to treat a local date and time as if it were UTC, which shifts the result by the zone's offset. The time zone converter compares clocks in two places.
Does Unix time count leap seconds?
No. Unix time treats every day as exactly 86,400 seconds, so leap seconds are not counted, and dates long before 1970 may use historical time zone offsets that differ between systems. To count days between two dates, use the date calculator.