How to Use
- Choose the conversion direction
Select whether to convert a timestamp to a date, or a date to a timestamp.
- Enter the value
Input a Unix timestamp number or select a date and time.
- View the result
Click Convert to see the result displayed in multiple formats.
What is a Unix timestamp?
A Unix timestamp (Unix time, POSIX time, Epoch time) represents the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC (the Unix Epoch) as a single integer. Because it points to the same instant everywhere on Earth regardless of time zone, daylight saving, or calendar notation, it has become the de facto standard for database storage, logging, API communication, and time comparison.
Why express time as a number?
- Simple comparison — deciding which of two moments came first is just an integer comparison.
- Easy arithmetic — adding or subtracting immediately yields the elapsed time in seconds.
- No ambiguity — as an absolute UTC time, there is no confusion over whether a value is local time or UTC.
10-digit (seconds) and 13-digit (milliseconds) forms are common; JavaScript and Java work in milliseconds by default, while Unix system calls use seconds.
Conversion Formula
Timestamps and dates convert in both directions using 1000 (the millisecond factor) as the bridge.
- Timestamp → date:
date = new Date(timestamp x 1000) - Date → timestamp:
timestamp = floor(UTC milliseconds / 1000)
Example: converting 1711324800 seconds gives 1711324800 x 1000 = 1,711,324,800,000 milliseconds → 2024-03-25 00:00:00 UTC. Conversely, 1970-01-01 01:00 converts to a timestamp of 3600, since 1 hour = 3600 seconds. Here timestamp is the seconds elapsed since the Epoch, x1000 is the millisecond conversion factor, and floor truncates the fractional part.