Sometimes days are not precise enough. How many hours did a support ticket stay open? How long did a machine run? How many hours until an online exam window closes? You need the exact time between two dates and times. This guide explains how to calculate it and gives practical examples, using our Date & Time Difference tool.
The method
- Write both date-times in the same time zone.
- Count full days between them.
- Add or subtract the remaining hours and minutes.
Example
From 3 March 2026, 4:30 pm to 6 March 2026, 9:15 am:
- 3 March 4:30 pm to 5 March 4:30 pm = 2 days
- 5 March 4:30 pm to 6 March 9:15 am = 16 h 45 min
- Total = 2 days 16 hours 45 minutes, or 64.75 hours
Totals for billing and reports
| Format | Value |
|---|---|
| Days, hours, minutes | 2 d 16 h 45 min |
| Total hours | 64.75 h |
| Total minutes | 3,885 min |
Total hours are what you need for billing or overtime; the breakdown is easier to read.
Practical uses
- Support and service: measure response and resolution times.
- Rentals: charge per hour for equipment or vehicles.
- Shifts and overtime: total hours across midnight; see the Working Hours Calculator.
- Online exams and submissions: know exactly how long is left.
- Parking and hotel stays: check charges.
Different time zones
If the two times are in different zones, as with international deadlines or flights, convert both first. The tool lets you pick a zone for each time. Read flight duration across time zones for examples.
Dates only
If you just need days, weeks or months between dates, the Date Difference Calculator is simpler.
Decimal hours
Convert minutes to decimals by dividing by 60. 45 minutes = 0.75 hours. Our Time Calculator helps add or subtract times.
Frequently asked questions
How do I calculate hours between two dates and times?
Find the full days, multiply by 24, then add the remaining hours and minutes.
How do I handle different time zones?
Convert both times into one time zone before subtracting.
How do I convert minutes to decimal hours?
Divide the minutes by 60.