When this tool helps
A duration is an amount of time, not a time on a clock. Use this tool to add two task lengths or subtract one elapsed amount from another. It normalises the result so, for example, 79 minutes contributes one hour and nineteen minutes.
Choose Add or Subtract, then enter hours, minutes or seconds for duration A and duration B. Blank components are treated as zero, but at least one component must be entered. This differs from the Work hours tool, which starts with clock times and an unpaid break.
What to enter
These are the candidate Android fields, not a form on this website. Editable fields in the app start empty; modes and units are selected separately.
- Add or subtract durations?
- Choose A + B or A − B.
- Duration A · hours, minutes, seconds
- Enter whole non-negative components as needed.
- Duration B · hours, minutes, seconds
- Unused components can remain blank.
Try this example after the update is available
The values below explain the calculation. They are not a quote, a live measurement or an automatic answer for your situation.
- Operation
- Add
- Duration A hours
- 2
- Duration A minutes
- 5
- Duration B minutes
- 79
Checked example result3h 24m 0s
Two hours five minutes plus seventy-nine minutes is two hours eighty-four minutes. Normalising sixty of those minutes gives three hours twenty-four minutes.
Formula and assumptions
Total seconds = hours × 3,600 + minutes × 60 + seconds; add or subtract, then normalise
- Components are whole numbers from 0 to 1,000,000. Larger minute and second components are allowed and normalised.
- Subtract calculates A minus B and keeps a negative sign when B is larger. No dates, time zones or clock rollover are modelled.
A common mistake to avoid
Do not enter 1.5 in an hours component to mean ninety minutes. Use 1 hour and 30 minutes, or enter 90 in the minutes component.
Find this tool in the Android update
- When you have the redesigned Android update, open Tools and search for Add / subtract time, or find it under Everyday.
- Open the tool, choose the mode or units relevant to your task, then enter your own values.
- Review the result and explanation. Use Calculate & save only if you want the calculation kept in local History; Copy result does not send it to our server.
This guide is an educational preview of the update in testing, not an announcement that Google Play has approved or published it. Calculations are in the native app; no web calculator or download is offered on this page.
Questions about Add / subtract time
Must minutes be below 60?
No. A value such as 79 minutes is accepted and normalised in the result.
What if I subtract a longer duration?
The result is negative, indicating that duration B is greater than duration A. The tool does not silently swap them.