Convert Unix Timestamp to Date and Back

Computers store time as a number: the seconds elapsed since midnight on 1 January 1970 UTC. That number turns up in server logs, API responses and databases, but it is unreadable at a glance, so this tool converts both ways. The “now” button fills in the current time, converting the number produces a UTC date-and-time string, and the reverse path turns a typed date back into Unix seconds. Output is deliberately in UTC so it matches server logs; for Iran local time add three and a half hours (210 minutes). This version works in seconds, not milliseconds, if you have a 13-digit value, drop the last three digits.

This tool runs entirely in your browser. No data is sent to any server.

How to use it

1. 1

   Press “now” for the current moment, or type the timestamp number into the box yourself.

2. 2

   Press convert to see the readable date and time (UTC).

3. 3

   For the reverse, write a date such as 2026-10-04 12:00 in the second box and convert it.

Frequently asked questions

Why does the output time differ from my clock?

The result is in UTC, because logs and APIs are written on that basis. For Iran local time add 3 hours 30 minutes.

My number has 13 digits and the answer is wrong. Why?

Unix time is counted in seconds, while 13-digit values are usually milliseconds. Drop the last three digits to get seconds.

What date range is supported?

Any value the browser can turn into a valid date, which in practice covers 1970 through several thousand years ahead. Negative numbers are dates before 1970.