Date Range Formula
To calculate hours between two dates, subtract the start date-time from the end date-time, then convert the elapsed milliseconds into hours.
Total hours = elapsed milliseconds / 3,600,000
Example
Start: June 1 at 9:00 AM. End: June 3 at 5:30 PM. The elapsed time is 56.5 hours, or 2 days, 8 hours, and 30 minutes.
When to Use It
- Measuring project windows
- Checking an overnight or multi-day shift span
- Comparing planned and actual time ranges
- Converting a date range into decimal hours
How to Review the Result
Check the source entries against the values shown in the calculator. Confirm the date, start time, end time, break minutes, hourly rate, threshold, and multiplier one field at a time.
Gross duration is the full time between start and end. Net duration is the amount left after the entered break is deducted. If those values do not match your expectation, correct the time or break entry before reviewing the final total.
Keep the Calculation Reproducible
When a result will be shared, record the inputs beside it. A clear note might include the pay period, shift dates, total break minutes, selected rate, and any extra-hour settings used.
For recurring work, use the same input format each time and keep each period separate. Recalculate after edits instead of adjusting the final number manually.