10 digits vs 13 digits
Unix seconds often use 10 digits, while JavaScript millisecond timestamps usually use 13 digits.
Unix Timestamp to Date
Convert 10-digit seconds or 13-digit milliseconds into readable local and UTC date-time values.
What this solves
Use this guide when a log, API response, or database field gives you a numeric timestamp and you need to understand the exact date.
How to use it
- Copy the timestamp from your log, API response, or database field.
- Open the main timestamp tool and paste it into the Timestamp to Date panel.
- Check whether the value is seconds or milliseconds.
- Copy the local, UTC, or ISO output that matches your workflow.
Seconds and milliseconds example
1700000000 1700000000000
1700000000 is seconds; 1700000000000 is milliseconds. Both can map to the same moment when interpreted with the correct unit.
If the result looks decades away, the value was probably interpreted with the wrong unit.
Common mistakes
Timezone expectations
Local time and UTC can show different clock values for the same moment.
Copied whitespace
Trim spaces or line breaks copied from logs before converting.
Unix timestamp to date FAQ
How do I know if a timestamp is seconds or milliseconds?
10-digit values are usually seconds; 13-digit values are usually milliseconds.
Why does UTC differ from local time?
They represent the same instant in different timezones.
Can I copy ISO output?
Yes. Use the main tool to copy ISO 8601 or another output template.