In SharePoint lists, you can calculate the time difference between two Date/Time columns using a calculated column formula. The key is to store both columns as Date and Time (not just Date) and use the DATEDIF or subtraction approach depending on the needed time unit.
Example
If you have columns:
- StartTime (Date and Time)
- EndTime (Date and Time)
Then create a Calculated column named Duration with this formula:
=([EndTime]-[StartTime])*24
This returns the difference in hours.
To get minutes, multiply by 24*60; for days, remove the multiplier.
Notes
- SharePoint stores dates as serial numbers, so subtracting two date/time values gives the difference in days (Microsoft Docs: Calculated Field Formulas).
- Ensure both fields include time values; otherwise, SharePoint assumes midnight and results may appear off.
- If you need to show the result as a friendly text like “2 hrs 15 mins,” concatenate parts:
=INT(([EndTime]-[StartTime])*24) & " hrs " & INT(MOD(([EndTime]-[StartTime])*24*60,60)) & " mins"
For Modern Lists or Power Apps
If you need more flexible formatting or time-zone handling, use a Power Apps customized form and calculate the difference using the DateDiff() function (reference).
In short:
Use a calculated column with date subtraction, multiply to the desired unit, and format as needed. Ensure both fields include time for accurate results.