DIY Cost Tools
Business Days Calculator
Count weekdays between two dates after subtracting weekday holidays that fall inside the interval.
How to use this calculator
- Replace the example values with your own measurements or planning assumptions.
- Keep every value in the unit printed beside its field.
- Select Calculate and review the result together with the formula and limitations below.
Formula and method
The start date is excluded and the end date is included. Saturdays and Sundays are removed, then the entered number of weekday holidays is subtracted.
Results are hidden whenever an input changes or validation fails, so an old answer cannot be mistaken for a current calculation.
Worked example
Start date = 2026-10-05; End date = 2026-10-16; Weekday holidays in the interval = 0 days. The calculator returns Business days = 9; Calendar days elapsed = 11; Weekend days = 2.
The worked example uses the same default values displayed in the calculator.
Limitations and safety
Frequently asked questions
Does the calculator include the start date?
No. It counts eligible weekdays after the start date through the end date, which is useful for elapsed workday planning.
Why might the real result differ?
Holiday calendars and working weekends vary by employer and location. Enter only holidays that land on counted weekdays, and confirm contractual or legal deadlines independently.
How should I round the answer?
Keep extra precision while planning, then round up when purchasing whole containers, bags, pieces, or stock lengths. Follow the output labels and supplier packaging.
Review notes and reference
Reviewed October 4, 2026. The formula was checked against the displayed worked example, and the script was tested for defaults, boundaries, invalid formats, condition-specific errors, and recovery. Reference: NIST Time and Frequency Division. Explanations and examples are original.