10 vs 13 digits
10 digits usually indicate seconds; 13 digits usually indicate milliseconds.
Milliseconds Timestamp Converter
Convert 13-digit millisecond timestamps and compare them with 10-digit Unix seconds to avoid unit mistakes.
What this solves
Use this guide when working with JavaScript Date.now(), frontend logs, analytics events, or systems that store milliseconds.
How to use it
- Copy the 13-digit timestamp from JavaScript, logs, or analytics data.
- Paste it into the main timestamp tool.
- Compare the millisecond and second outputs.
- Copy the correct unit for the target API or report.
Milliseconds example
1700000000000 1700000000
1700000000000 milliseconds equals 1700000000 seconds when divided by 1000.
If a date appears far in the future, a millisecond value may have been treated as seconds.
Common mistakes
Dividing twice
Do not divide by 1000 again if the tool already gives seconds output.
Unexpected future dates
Large values can produce unrealistic dates if interpreted with the wrong unit.
Milliseconds timestamp FAQ
What does Date.now() return?
JavaScript Date.now() returns milliseconds since the Unix epoch.
How do I convert milliseconds to seconds?
Divide the millisecond timestamp by 1000, or copy the seconds output from the tool.
Why are there 13 digits?
Milliseconds need three extra digits compared with Unix seconds.