Time Difference Calculator
This comprehensive tool lets you calculate the exact duration between two specific points in time, even if they are in different time zones. It's essential for coordinating international meetings, planning travel itineraries, or tracking deadlines across the globe. The calculator handles the complexities of time zone conversions, so you get an accurate and easy-to-understand result.
Resulting Duration
1d 5h 0m 0s
Total Duration in Decimal Hours: 29.0000
This represents the total duration as a single number, which can be useful for billing or data analysis.
How the Calculation Works
Converting Everything to UTC
Time zones and daylight saving rules can shift the local clock, so the calculator first converts both of your selections into Coordinated Universal Time (UTC). Working in a single reference time lets us compare the two moments accurately.
- Build the local datetime: The selected date and HH:MM time are combined for each location.
- Convert to UTC: Using the chosen time zone, we translate that local moment into UTC.
- Calculate the gap: The UTC timestamps are subtracted to get a raw difference in milliseconds, which is then turned into days, hours, minutes, and seconds.
Example Calculation
Start: December 1, 2025 at 09:00 (UTC) → December 1, 2025 at 09:00 UTC
End: December 2, 2025 at 14:00 (Europe/London) → December 2, 2025 at 14:00 UTC
- The UTC timestamps differ by 104,400,000 ms.
- That converts to 1 days, 5 hours, 0 minutes, and 0 seconds.
- Expressed as a single number, the span is 29.0000 decimal hours.