Dates & Time

Time Calculator (Elapsed & Add/Subtract)

Two tools in one. The difference mode gives elapsed time between two clock times, and the add/subtract mode applies a duration to a start time.

How to use
  1. Pick difference mode or add/subtract mode.
  2. Enter your start time, and an end time or a duration.
  3. Use the decimal hours and total minutes outputs as needed.
End
Elapsed duration
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Decimal hours
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Total minutes
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Total seconds
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Date math uses your inputs as given; check time-zone and leap-year edge cases.
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How it's calculated

elapsed = end − start (+24h if negative); result = start ± duration

start/end = clock times, duration = hours:minutes:seconds added or subtracted. Day rollovers are tracked as ±1 day.

Common questions

How do I calculate hours between two times?

Enter the start and end times in 24-hour format and the difference mode returns the elapsed hours, minutes, and decimal hours.

What is 8:30 plus 5 hours 45 minutes?

Use add mode with a start of 8:30 and a duration of 5:45 to get 14:15, and the tool flags any roll-over past midnight.

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