Time Duration Calculator
Calculate the exact duration between two clock times. Handles midnight crossovers automatically.
Time Inputs
24-hour (hh:mm:ss)
24-hour (hh:mm:ss)
How It Works
Both times are converted to total seconds from midnight, then the difference is computed. If the end is earlier than the start, 24 hours (86,400 s) is added — indicating the end is the next calendar day.
Decimal hours = total seconds ÷ 3600. For example, 1h 30m = 1.5h — the format used in billing and payroll.
Formula
Duration = End − Start
If Duration < 0: Duration += 86400s
Decimal = Duration ÷ 3600
Disclaimer: For informational purposes only.
About the Time Duration Calculator
This time duration calculator handles date arithmetic, time zones, calendars, and scheduling utilities. Calculate the exact duration between two clock times. Handles midnight crossovers.
Use for planning events, deadlines, workdays, and time-zone aware calculations.
Adjust the inputs above to model your specific scenario with the Time Duration Calculator.
Explore More
Related Calculators
Clock
Full-screen live digital clock with timezone support, 12/24h format, and millisecond precision.
Cron Schedule Generator
Build, validate, and understand cron expressions with a visual builder and execution forecast.
Hours & Minutes Calculator
Add or subtract multiple time durations. Perfect for tracking project or travel time.
Reaction Time Calculator
Measure your visual reflex speed in milliseconds and compare to gamer and F1 benchmarks.
Stopwatch
Precise stopwatch with lap splits and millisecond accuracy.
Sunrise Sunset Calculator
Find sunrise, sunset, and day length for any location and date.