mockstack.

Time Converter

UNIX · ISO 8601 · TIME ZONES ← Developer & Data

Mode

Read Numbers As

Auto goes by length: up to 11 digits is seconds, 13 is milliseconds, 16 is microseconds, and 19 is nanoseconds.

Time Zone

Dates typed without an offset are read in this zone, and the results show the time here as well as in UTC.

Paste a Unix timestamp or a date to see it every common way, or pick a date to get its timestamp.

Now

Timestamp or Date

READY RUNS LOCALLY

About the Time Converter

Converts Unix timestamps to dates and dates to timestamps, and shows one moment across as many time zones as you like, with daylight saving worked out for each.

Every Setting

Timestamp or Date: Takes a Unix timestamp, an ISO 8601 date like 2026-09-23T14:30:00Z, an RFC 2822 date from an email or HTTP header, or most dates written out in words. The calendar button picks a date and time instead. Now fills in the current moment, and the Now bar above counts in real time.
Results: Unix seconds and milliseconds (and microseconds or nanoseconds when you paste them), ISO 8601 in UTC and in your chosen zone, RFC 2822, the HTTP date format, a readable date, how long ago or how far ahead it is, and the weekday, day of the year, and ISO week. Each has a Copy button.
Read Numbers As: Auto decides the unit by the number of digits, which is right for any date between 1973 and 5138. Choose a unit when a number is ambiguous, such as a small test value.
Time Zone: The zone for dates typed without an offset and for the zone rows in the results. It starts as your own.
Time Zones: Set a date and time and the zone it is in, and every zone in the list shows the same moment with its offset from UTC, its abbreviation, whether daylight saving is on, and whether it falls on the day before or after. Now follows the clock until you change the time. Add a Zone takes a city or region, the × on a row removes it, and Reset List brings back the starting set.
Clock: 12-hour or 24-hour times in the zone list.

Common Questions

Is my timestamp in seconds or milliseconds?: Count the digits. A current timestamp in seconds has 10 and one in milliseconds has 13. JavaScript’s Date.now() is milliseconds; most databases and Unix tools use seconds.
What happens in 2038?: Signed 32-bit timestamps run out at 2147483647, which is 03:14:07 UTC on January 19, 2038. Paste it to see. Systems that store time in 64 bits are not affected.