Add or subtract time durations
To calculate the difference between two times, you subtract the start time from the end time. If the minutes of the end time are less than the start time, you borrow 60 minutes (1 hour) from the hours section to complete the subtraction.
Add the hours and minutes separately. If the total minutes equal or exceed 60, divide the total minutes by 60. The quotient is added to the hours, and the remainder becomes the final minutes. (e.g., 2 hours 45 mins + 1 hour 30 mins = 3 hours 75 mins = 4 hours 15 mins).
The 12-hour clock divides the 24-hour day into two periods: AM (before noon) and PM (after noon). The 24-hour clock runs continuously from 00:00 (midnight) to 23:59 (one minute before midnight), eliminating the need for AM/PM designators.
© 2026 CalculatorZon - Free Online Calculators. Fast, accurate and interactive.