Convert Unix Timestamps to Dates and Back, with Time Zones, Seconds and Milliseconds

Databases and APIs often store time as a long number counted from 1 January 1970 UTC, which is unreadable until you convert it.

The unit of the number

A 10-digit number is usually seconds and 13 digits is milliseconds. The tool guesses the unit from the size of the number and lets you set it yourself when it guesses wrong. Microseconds and nanoseconds are supported too.

Time zones

Choose an IANA zone such as Asia/Bangkok to see local time. A date entered without a zone uses the one you selected.

Other things shown

• Relative time, such as how many hours ago.
• The ISO week and the day of the year.

No server needed

Everything is calculated in your browser.