Add or subtract hours and minutes from a start time to get the resulting clock time.
How time duration is worked out
Enter a start time and an amount of hours and minutes to add or subtract, and this calculator returns the resulting time, wrapping correctly around midnight.
Useful for scheduling, cooking and shift planning.
A worked example
On the values this calculator opens with, the result time is 11:30. Alongside it, Total minutes changed comes out at +150 min. Change any field and every figure updates as you type.
Step by step
- Enter the start time.
- Choose add or subtract and the hours and minutes.
- Read the resulting time.
The formula
result = start ± (hours×60 + minutes), wrapped to a 24-hour clock
Common questions
How do I add time to a clock time?
Convert everything to minutes, add, then convert back — wrapping past midnight if needed. The tool handles this.
Does it handle crossing midnight?
Yes — the result wraps around a 24-hour clock in both directions.
How is this different from the hours calculator?
This adds a duration to a time; the hours calculator finds the duration between two times.