Counting business days is easy once you know the method. Here is how to do it by hand and in Excel.
Updated November 2026
What counts as a working day
A working day, or business day, is a day on which work normally happens, usually Monday to Friday. Counting them matters for delivery dates, invoice terms, project plans and leave. Use the working days calculator for a quick answer, or build it yourself with the steps below.
The basic method
2026 has 365 days. It starts on a Thursday, so it contains 52 full weeks plus one extra Thursday. That gives 52 x 5 + 1 = 261 Monday-to-Friday days. If 10 holidays fall on weekdays, there are 251 working days.
Excel: NETWORKDAYS
Excel counts working days with the NETWORKDAYS function. Both start and end dates are included. For the whole of 2026: =NETWORKDAYS(DATE(2026,1,1),DATE(2026,12,31)) returns 261. To skip holidays, list them in a range such as E2:E11 and add it as the third argument: =NETWORKDAYS(A2,B2,E2:E11).
Adding working days to a date
To find a due date, use WORKDAY: =WORKDAY(start, days, holidays). For example, an invoice due 30 working days after a start date can be found with one formula, with weekends and listed holidays skipped.
Six-day weeks and custom weekends
Some workplaces work Monday to Saturday or have different weekend days. Excel’s NETWORKDAYS.INTL takes a weekend code, and our calculator has a Monday-to-Saturday option. For 2026 a six-day week has 365 – 52 = 313 working days before holidays, because only the 52 Sundays are removed.
Common mistakes
- Forgetting that both the start and end dates count.
- Not listing holidays that fall on weekdays. Holiday dates change by country, state and employer.
- Counting a holiday that lands on a weekend twice.
- Mixing calendar days and business days in contract terms. Check which one the contract means.
Turn working days into pay with the salary to hourly calculator, or log hours with the time card calculator.
Frequently asked questions
How do I calculate working days between two dates?
Count the calendar days, remove weekends and subtract weekday holidays. In Excel use NETWORKDAYS.
How many working days are in 2026?
261 Monday-to-Friday days before holidays.
Does NETWORKDAYS include the start date?
Yes. Both the start and the end date are counted.
How do I add working days to a date?
Use =WORKDAY(start, days, holidays).