Dates & time
ISO day-time duration converter
Convert a fixed ISO-style day/time duration to seconds and back.
A clear answer. Here’s how.
Supports an optional leading minus sign, whole days/hours/minutes and seconds with up to three decimal places, such as -P1DT2H or PT0.125S. Standalone whole weeks (P2W) are also accepted. Years and calendar months are excluded because their elapsed lengths vary. Uses fixed 24-hour days; seconds input rounds to milliseconds. This is a bounded duration subset, not a parser for every ISO 8601 representation.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Direction
- Duration → totals
- Duration (for example P2DT3H30M or PT45.5S)
- P2DT3H30M
Example result
- Normalised fixed duration
- P2DT3H30M
- Total seconds
- 185,400
- Total minutes
- 3,090
- Total hours
- 51.5
- Fixed 24-hour days
- 2.14583333333
Calendar years/months and daylight-saving changes are excluded. Precision is milliseconds.