Add or subtract time from any hour. Find the duration between two times.
No download required.
AlarmO'Clock's time calculator makes it easy to work with time arithmetic. Use the Add/Subtract tab to find what time it will be after adding or subtracting a duration from any starting time — useful for scheduling, travel, and shift planning.
Use the Time Between tab to calculate the exact number of hours and minutes between two times. Results automatically account for midnight crossings, so you can calculate overnight durations without any guesswork.