How duration adder works
Add durations written as hours:minutes or hours:minutes:seconds.
Formula and convention
Convert each duration to seconds, add the values, then format total hours, minutes, and seconds.A worked example
1:30 plus 0:45 plus 0:15 totals two hours thirty minutes.
Scope and precision
Two-part inputs mean hours:minutes, not minutes:seconds. Minutes and seconds must be 0 to 59. No time-zone interpretation is applied.
Displayed results may be rounded. Inputs are processed locally and are not stored by this site. Keep the original values if you need to reproduce the result.
Why might another tool give a different result?
Compare unit definitions, rounding, period assumptions, and input values. This page states the convention used by this calculator.