How time duration is calculated
The calculation measures the difference between two 24-hour clock readings. If the ending time occurs on the following calendar day, selecting crosses midnight adds 24 hours (1,440 minutes).
The resulting elapsed time is presented in decimal hours for payroll calculations alongside conventional hours and minutes.
Worked example
Starting at 08:30 and finishing at 17:15 on the same day:
The total elapsed duration is 8 hours and 45 minutes, which equals 8.75 decimal hours, 525 total minutes or 31,500 seconds.
Inputs for the time calculator
Start time
The start time of the event or shift in 24-hour format.
End time
The finishing time in 24-hour format.
Crosses midnight?
Choose yes if the shift spans into the following calendar morning.
CALCULATOR QUESTIONS
Time calculator questions
How do I calculate an overnight nightshift?
Enter your starting time (e.g. 22:00) and finish time (e.g. 06:00), then choose 'Yes' for crosses midnight to compute an 8-hour shift.
Why are decimal hours useful?
Payroll systems multiply decimal hours by hourly rates to calculate pay accurately (e.g. 8.75 hours times £15/hr).