What's Unix Epoch time?

The number of seconds (or milliseconds, in some APIs) since midnight UTC on January 1, 1970. It is the standard way computers represent a point in time, language-agnostic, time-zone-free, easy to compare and do arithmetic on.

How does the tool know if my number is seconds or milliseconds?

By a threshold check. If the number is larger than 100,000,000,000 (about year 5138 in seconds, but only ~1973 in milliseconds), it is treated as milliseconds. Below, as seconds. Works for any time after 1973 and before ~5138. Outside that range you may need to pick the unit manually in your own code.

My converted date shows the wrong time zone. Why?

We display three views: ISO (UTC), UTC string, and your browser's local time. The conversion math is identical, the only difference is which timezone formatting is applied. Pick the line that matches your context.

What's the 'Year 2038 Problem'?

32-bit signed integers overflow at 2,147,483,647 seconds past the epoch, which is 03:14:08 UTC on January 19, 2038. Old systems using 32-bit `time_t` will wrap around to negative numbers (looking like 1901). Modern 64-bit systems push the limit out to ~292 billion years, so the problem mainly affects legacy embedded hardware that has not been updated.

Where is the conversion done?

Entirely in your browser via JavaScript's built-in `Date` object. Nothing leaves your device.

Free, no signup, no rate limit. Timestamp input capped at 15 digits, date string at 100 characters.

Utility

Epoch Time Converter

Convert Unix Timestamp to Date

Input

Mode

Unix Timestamp

Convert between Unix Epoch Timestamps (seconds/millis) and human-readable dates.

Terminal

Console ready. Execute a command to see output...

About Epoch Time Converter

Time is a Number

In computing, time often starts at January 1, 1970 (UTC). This is the "Unix Epoch". The timestamp is simply the number of seconds that have passed since then.

The Year 2038 Problem

32-bit systems will run out of seconds on January 19, 2038. This is the "Y2K" of our generation. Most modern systems (64-bit) are already safe until the universe likely ends.

How to use Epoch Time Converter

Pick the mode
Timestamp → Date if you have a number, Date → Timestamp if you have a date string.
Enter the value
Timestamp: digits only (seconds or milliseconds). Date: any format JavaScript Date accepts (ISO 8601, short date, full string). Optional Set Local Time / Set UTC Time buttons prefill the current moment.
Hit Convert
Timestamp → Date shows ISO, UTC, and your local time. Date → Timestamp shows both seconds and milliseconds.
Copy what you need
Each line is selectable in the terminal panel. Match the format your downstream system expects.

Frequently Asked Questions

: The number of seconds (or milliseconds, in some APIs) since midnight UTC on January 1, 1970. It is the standard way computers represent a point in time, language-agnostic, time-zone-free, easy to compare and do arithmetic on.