Reverse Time Calculator: Subtract Duration from Time

  • Adam
  • January 9, 2026

Calculate the starting time by subtracting a duration from an ending time. Perfect for planning when to start a task to finish by a specific deadline.

Reverse Time Calculator

e.g., Task takes 1h 30m
You should start at
--:--
--
Start
← Duration →
End

Formula

$$ \text{Start Time} = \text{End Time} - \text{Duration} $$

Related Calculators