Start by agreeing on three things
Before you count anything, settle three questions. Which days are open each week? Which holidays or closures apply? And do the first and last dates count?
Most disagreements about business days come from different answers to those questions, not from bad arithmetic. A bank, a court and your employer can all give different counts for the same two dates, and each can be right under its own rules.
The whole-weeks shortcut
For long ranges, count in weeks. Every full week has five weekdays on a Monday to Friday schedule. Count the full weeks, multiply by five, then add the weekdays in the leftover days.
Say a range runs 30 days, counting both ends, and starts on a Wednesday. That's 4 full weeks (20 weekdays) plus 2 leftover days. The leftover days are Wednesday and Thursday, both weekdays, so the total is 22 before holidays.
Formula notes
Weekdays = full weeks x 5 + weekdays in the remaining days
Taking out holidays
Next, subtract holidays, but only the ones that land on a weekday inside your range. A holiday on a Saturday is already gone from the weekday count.
Watch for observed days. In 2026, July 4 is a Saturday, so federal offices close on Friday, July 3 instead. Count July 3 as the holiday. Private employers set their own policies, so check yours rather than assuming they follow the federal calendar.
Counting forward to a deadline
When a rule says something is due in a number of business days, you usually start the day after the trigger date. Count each open day as one, skip weekends and holidays, and stop when you reach the number.
Five business days from Monday, October 5, 2026 is not Monday, October 12. That day is Columbus Day, a federal holiday, so the fifth business day is Tuesday, October 13. To check a count like this, our business days calculator gives the number of working days between the two dates.
Doing it in a spreadsheet
Excel and Google Sheets have NETWORKDAYS, which counts weekdays between two dates including both ends, minus any holiday dates you list in a range. WORKDAY goes the other way and returns the date a set number of workdays later.
Both have INTL versions that let you choose a different weekend, such as Friday and Saturday. Keep the holiday list in its own column so you can update it each year.
A typical formula looks like =NETWORKDAYS(A2, B2, H2:H12), with the start date in A2, the end date in B2 and your holiday dates in H2 to H12. If your rule skips the start date, use A2+1 as the start. That small change is easy to forget and accounts for many off-by-one deadlines.
Mistakes that move deadlines
A one-day slip on a deadline can matter a lot. These are the usual causes.
- Counting the trigger day when the rule says to start the next day.
- Subtracting a weekend holiday that was never in the weekday count.
- Using the actual holiday date instead of the observed weekday.
- Assuming a private company follows the federal holiday calendar.
- Using last year's holiday list for a range in the new year.
Frequently asked questions
Is the day after Thanksgiving a business day?
It isn't a federal holiday, so federal offices treat it as a workday. Many private employers give it off, so check your own calendar.
How many weekdays are in a year?
Between 260 and 262, depending on which weekday the year starts on and whether it's a leap year. 2026 has 261.
What is the difference between NETWORKDAYS and WORKDAY?
NETWORKDAYS returns how many workdays fall between two dates. WORKDAY returns the date that is a given number of workdays after a start date.
Do banks count Saturday as a business day?
Banks set their own business days, and many treat only weekdays outside holidays as business days. Check your bank's policy for deposits and transfers.
How do I count business days in another country?
Use that country's weekend and its own public holidays. In places with a Friday and Saturday weekend, Sunday is a normal working day.
References
These sources support the method or guidance used for Business Days Calculator. Verify time-sensitive rules at the source.
Try the calculator
Open Business Days Calculator, enter your scenario, and compare its supporting rows with this guide's method and checks.