Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa. Supports seconds and milliseconds — all in your browser, no upload, instant results.
About the Unix Timestamp Converter
This Unix timestamp converter runs entirely in your browser. Enter a Unix timestamp to see the corresponding human-readable date, or pick a date and time to get the matching Unix timestamp. The current timestamp updates live every second. Nothing is uploaded to a server — the conversion happens instantly with JavaScript on your device.
What is a Unix timestamp?
A Unix timestamp (also called Unix time or POSIX time) is the number of seconds that have elapsed since the Unix epoch — midnight UTC on January 1, 1970. It is a simple, timezone-independent way to represent a point in time as a single integer. Because it ignores leap seconds, the count increases by exactly 86400 each UTC day.
Many systems also use millisecond timestamps, which are 1000 times more precise. JavaScript's Date.now() and Date.getTime() both return milliseconds, while command-line tools and APIs often use seconds. This tool handles both — just pick the unit from the dropdown.
The Y2K38 problem
On systems that store Unix time as a signed 32-bit integer, the maximum representable value is 2147483647, which corresponds to 03:14:07 UTC on January 19, 2038. After this moment, the value overflows and wraps to a negative number, which many programs interpret as a date in 1901. This is known as the Year 2038 problem (or Y2K38). Modern 64-bit systems are unaffected because their timestamp range extends hundreds of billions of years into the future.
How to use the converter
- Timestamp → Date: Type a Unix timestamp, choose Seconds or Milliseconds, then click Convert to see the local time and UTC time.
- Date → Timestamp: Pick a date and time using the datetime picker, then click Convert to see the Unix timestamp in both seconds and milliseconds.
- Click Use current time to fill the date picker with the current local time.
- Click Copy last result to copy the most recent output, or Clear to reset.
Frequently asked questions
Does this tool upload my data? No. All conversion happens locally in your browser. Your input never leaves your device.
Why does the date look different from another tool? Dates are shown in both your local timezone and UTC. If a result seems off, check which timezone the other tool is displaying. The timestamp itself is always timezone-independent.
Can I convert timestamps before 1970? Yes. Negative Unix timestamps represent dates before the epoch. For example, -1 is one second before midnight on January 1, 1970.
What about leap seconds? Unix time ignores leap seconds, so every UTC day is treated as exactly 86400 seconds. This keeps the count simple but means Unix time can drift slightly from actual atomic time.