FORMULAS, SHAPES, TIME, AND NUMBER TOOLS
Time Duration Calculator
Calculate the net duration between decimal 24-hour start and end times, including an overnight period and an optional break.
Review your result
Your result
Ready when you are.
Enter your values and choose Calculate. Your inputs stay on this device.
How it works
Duration = end − start, adding 24 hours when the interval crosses midnight, then subtracting the break.
Assumptions and limits
One continuous interval only. Decimal 9.5 means 09:30; time zones, dates, attendance policy, and paid-break rules are excluded.
About this calculator
This duration tool handles a single same-day or overnight interval and keeps any deducted break explicit.
What this tool helps you check
Find elapsed time between two clock readings, including an overnight interval when selected.
How to use it
- Review the formula and assumptions shown for this time duration calculator.
- Enter start and end as 24-hour decimal values and an unpaid break if relevant.
- Calculate and read gross and net hours separately.
- Use an official attendance record for payroll, legal, or institutional purposes.
Source and update
Last reviewed: 2026-08-22
This tool performs the stated formula locally in your browser using the values you enter.
Frequently asked questions
What does this time duration calculator calculate?
This duration tool handles a single same-day or overnight interval and keeps any deducted break explicit.
How should I interpret the result?
Read gross and net hours separately. The result changes whenever an input or assumption changes.
Is the result official or guaranteed?
Use an official attendance record for payroll, legal, or institutional purposes.
Keep exploring