Calculating Time Intervals

This calculator finds the duration between two clock times in a 24-hour day. Both inputs are converted to minutes since midnight, subtracted, and the result is presented as hours and minutes, total minutes, decimal hours, and seconds. If the end time falls before the start time, the interval is treated as crossing midnight.

Decimal Hours for Work and Payroll

Timesheets and payroll systems typically want time in decimal hours — 8.5 hours rather than 8h 30m. Multiply the decimal hours by your hourly rate to check a pay stub, or sum several intervals to total a workweek.

Planning a Day

Use the share-of-day chart to see how much of a 24-hour period a task occupies. A standard 8.5-hour shift is just over a third of a day — a useful perspective when planning study blocks, travel, or overnight shifts that span midnight.