Units
Time units converter
Convert hours, days, and milliseconds without inventing a month length.
This tool processes files and text locally in your browser. Your content is not uploaded or stored by this site.
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What this tool does
The second is the base. A day is exactly 86,400 seconds. A week is seven of those days. Years, months, and leap seconds are refused because they are not fixed.
How to use it
- Enter the duration.
- Pick source and destination units.
- Convert and copy the JSON.
Supported input
- A number and two time units from the menu
Output
- JSON with the converted duration plus every other unit in the family
Privacy
This tool processes files and text locally in your browser. Your content is not uploaded or stored by this site.
ConvertPass does not include your input in analytics, URLs, or error reports. Encoding: Decimal numbers / SI second. Limit: A single duration (4.0 KB).
Limitations
- This is not the duration calculator’s ISO-8601 parser, and not the date-difference weekday count.
- Months and years are not listed. February is not 30 days.
- Leap seconds and sidereal days are not modelled.
Example
2 hours → seconds
{
"result": 7200,
"formatted": "2 h = 7200 s"
}
Troubleshooting
- I needed P1M or a civil month
- Use the duration calculator, which will still refuse months, or pick two calendar dates in date difference.
FAQ
Is a day always 24 hours here?
Yes, 86,400 seconds. DST does not apply because there is no timezone.
How is this different from the duration calculator?
That tool parses 1h 30m and ISO-8601. This tool only converts a number between named SI-style units.
Can I convert UNIX timestamps?
Use the UNIX timestamp tool. This page is a span, not a clock reading.
Why no year?
A Julian year is 365.25 days and a calendar year is not. ConvertPass will not pick one quietly.
Related tools
- Duration calculator
Turn messy duration strings into seconds, clocks, and ISO-8601.
- UNIX timestamp converter
Translate UNIX time and ISO-8601 without a timezone guessing game.
- Date difference
Count days and weekdays between two dates without a spreadsheet.
Related formats
Last reviewed 16 August 2026. Report a problem. Reports do not include your input.