Date Converter Online — ISO, Local and Unix Time
Convert a date string or Unix timestamp into ISO, local time, Unix seconds and milliseconds.
About this tool
Numeric input is detected as common epoch seconds or milliseconds; other input uses the browser Date parser.
How to use
- Enter or select the required input.
- Run the tool with the intended options.
- Review the result before using or downloading it.
Features
- ISO UTC output.
- Browser-local date display.
- Unix seconds and milliseconds.
Common use cases
- Debug API dates.
- Compare time zones.
- Convert log timestamps.
Common issues and tips
- Free-form date parsing depends on browser rules.
- Local output uses the current device time zone.
Privacy
Processing runs locally in your browser. Input is not uploaded to Tools12345.
Frequently asked questions
Are numeric values seconds or milliseconds?
Common smaller epoch values are treated as seconds.
Is ISO output UTC?
Yes.
Why does local time differ?
It uses the device time zone.