Date & time duration
Count calendar days or elapsed time between explicit-offset instants.
Tool guide
How to use Date & time duration
Count calendar days or elapsed time between explicit-offset instants.
- Enter the values and choose the operation or units. Read the supported limits beside the inputs; try the labelled sample to see an example.
- Calendar days and elapsed 24-hour days differ around clock changes. Month/year durations are not inferred.
- Choose Calculate duration. Review the result, then download the text result. Editing inputs invalidates old results.
- Calculations are local and unmetered. Inputs and results are not uploaded or saved to your account; leaving the page clears them. Downloaded files remain on your device.
Common questions
What are the limits of Date & time duration?
Years 0001–9999. Dates use YYYY-MM-DD. Instants need T plus explicit Z or ±HH:MM; no leap seconds. Calendar days and elapsed 24-hour days differ around clock changes. Month/year durations are not inferred.