Off-Day Calculator — Working Days vs Non-Working Days
Enter the total calendar days in a period, your working-days-per-week schedule, and any additional public holidays to get the exact split between working days and off days.
Working days per week
Calendar days minus weekends and holidays
73%
workingWorking days
73.3%
Weekend days
26.7%
- 1
Off-days per week
7 − 5 = 2Number of non-working days in each standard week. - 2
Weekend days from full weeks
4 × 2 = 8 - 3
Weekend days from partial week
max(0, 2 − 5) = 0 - 4
Total off days
8 + 0 = 8 - 5
Working days
30 − 8 = 22
How does this calculator work?
Working days = calendar days − (weekend days) − (public holidays). For a Mon–Fri schedule, weekend days ≈ 2/7 of the period. A 30-day month has about 21–22 working days; a 365-day year has about 261 working days before holidays. Enter your period length, schedule, and holiday count to get the exact breakdown.
Formula
How this is calculated
The calculator first converts the period into full ISO weeks plus any remaining calendar days. For each full week it subtracts the off-days-per-week (7 minus your working schedule: 2 for Mon–Fri, 1 for Mon–Sat, etc.). The remaining calendar days after the last full week are treated as working days first — this is a standard approximation used in payroll and project planning when the exact start day of the week is unknown.
Public holidays and closures are subtracted last, capped so they do not exceed the number of already-identified working days (holidays that fall on weekends are not double-counted). The result is the number of true working days, weekend days, and holiday days in the period.
This method gives the same result as a Mon–Fri calendar count when working days per week is 5, subject to the assumption about remaining days. For legally precise business-day counts — particularly in bond settlement, options expiry, or derivative contracts — consult the specific day-count convention (Actual/Actual, 30/360, Actual/360, etc.) that applies to your instrument.
Frequently asked questions
A standard Mon–Fri schedule gives approximately 21–22 working days per 30-day month and about 261 working days in a 365-day year (before public holidays). The exact count varies by month length and which day of the week the period starts.
Interest accruals, bond coupons, loan repayments, and derivatives settlements often use specific day-count conventions that distinguish calendar days from business days. Knowing the working-day count in a period prevents miscalculating accrued interest or settlement dates.
This calculator subtracts holidays from what remains after weekends, so a holiday that coincides with a weekend day is not double-counted. In practice, many countries observe a substitute weekday when a public holiday falls on a weekend — add those substitute days to the holiday count for an accurate working-day total.
Also known as
TG we-Calculate Editorial Team. (2026). Off-Day Calculator — Working Days vs Non-Working Days [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/off-day-calculator
TG we-Calculate Editorial Team. "Off-Day Calculator — Working Days vs Non-Working Days." TG we-Calculate. 2026. https://we-calculate.com/calculator/off-day-calculator.
TG we-Calculate Editorial Team, "Off-Day Calculator — Working Days vs Non-Working Days," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/off-day-calculator
@misc{wecalculate_off_day_calculator, title = {Off-Day Calculator — Working Days vs Non-Working Days}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/off-day-calculator}}, year = {2026}, note = {TG we-Calculate} }
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