Time Duration Calculator
Find exactly how much time passes between a start and an end — in days, hours and minutes, and as total hours, minutes or seconds.
How to use the Time Duration Calculator
- Enter the start date and time.
- Enter the end date and time.
- Read the duration and the totals.
How it works
The calculator converts both moments to minutes and subtracts them: duration = end − start. The difference is then split into whole days (1,440 minutes each), hours (60 minutes) and minutes. Because dates are included, spans across midnight, month ends and leap days are handled correctly.
Times are treated as local clock times without a time zone. If a daylight saving change happens in between, the real elapsed time can differ by one hour.
Common durations
| Duration | Hours | Minutes | Seconds |
|---|---|---|---|
| 1 hour | 1 | 60 | 3,600 |
| 8-hour shift | 8 | 480 | 28,800 |
| 1 day | 24 | 1,440 | 86,400 |
| 1 week | 168 | 10,080 | 604,800 |
| 30 days | 720 | 43,200 | 2,592,000 |
Frequently asked questions
How many hours are between 9 AM and 5:30 PM?
8.5 hours (8 hours 30 minutes).
How do I calculate time across midnight?
Include the dates: 10:00 PM on one day to 6:00 AM the next is 8 hours.
How many minutes are in a day?
1,440 minutes (24 × 60).
How many seconds are in a week?
604,800 seconds.
How do I add up several durations?
Convert each one to minutes, add them, then divide by 60 for hours. 1 h 45 min + 2 h 30 min = 105 + 150 = 255 minutes = 4 h 15 min.