How to count business days for a deadline
In short: To count business days to a deadline, start with the day after the event, skip Saturdays, Sundays and any holidays that apply, and the day you reach on the last count is the deadline. 10 business days from Monday, October 5, 2026 is Monday, October 19 counting weekdays only, and Tuesday, October 20 if Columbus Day, October 12, is a day off.
To count business days for a deadline you need three decisions before any arithmetic: which day is day zero, which days are not business days, and when on the last day the deadline ends. Get those right and the count is simple. Get one wrong and you are a day early or, worse, a day late. This guide sets out each decision with worked examples for October 2026, the holiday rule that moves deadlines in 2027, and how to make Excel agree with the business days calculator.
How to count business days, step by step
- Find day zero. It is the day of the event that starts the clock: the day you received the notice, signed, or ordered.
- Count from the next day. The first business day after day zero is day 1.
- Skip what is not a business day. Saturdays and Sundays, and the holidays that apply to whoever has to act.
- Stop at the last number. The day you reach is the deadline, unless the wording says otherwise.
Say a notice arrives on Monday, October 5, 2026 and asks for an answer within 10 business days. Tuesday the 6th is day 1, Friday the 9th is day 4, the weekend is skipped, and Monday the 12th is day 5 if you count every weekday. Day 10 is then Monday, October 19. But October 12, 2026 is Columbus Day, a federal holiday, and if it is a day off the count moves one day on, to Tuesday, October 20.
Why the count starts the day after
Counting the event day as day 1 is the most common mistake, and it makes every deadline one day too early. The federal courts' rule on computing time, Rule 6(a) of the Federal Rules of Civil Procedure, tells you to exclude the day of the event that triggers the period, count every day, and then:
include the last day of the period, but if the last day is a Saturday, Sunday, or legal holiday, the period continues to run until the end of the next day that is not a Saturday, Sunday, or legal holiday.
Rule 6 counts calendar days and governs court deadlines, but its starting point, the day after the event, is the same one the business days calculator uses when it adds days to a date. A contract or a statute can set its own method, so read its definition of "business day" first; if it has one, it wins.
"Within 10 business days", "by" and "no later than"
"Within 10 business days" means on or before day 10, so the answer above is on time on October 19 or 20, not only on that day. "By" and "no later than" a date mean the same. What the words rarely say is when the day ends. Some deadlines end at close of business, some at 11:59 p.m., and an online portal ends whenever its clock says. For an online deadline, check the time zone: 11:59 p.m. Eastern is 8:59 p.m. in California, so someone in Los Angeles who waits until late evening has already missed it.
Also check whether the deadline is for sending or for arriving. "Received within 10 business days" leaves less time than "postmarked within 10 business days" by however long the post takes.
Do business days include holidays? The observed day rule
A holiday on a weekday is skipped like a weekend, as long as it is a holiday for whoever has to act. Federal offices close on the federal holidays the Office of Personnel Management lists, eleven in 2026. When a holiday lands on a weekend, OPM's federal holidays page sets the day off for most federal employees:
If a holiday falls on a Saturday, for most Federal employees, the preceding Friday will be treated as a holiday for pay and leave purposes.
A Sunday holiday moves to the Monday. July 4, 2026 is a Saturday, so Friday, July 3 is the federal holiday, and 3 business days from Wednesday, July 1 is Monday, July 6 counting weekdays only but Tuesday, July 7 with the federal holiday skipped. 2027 has four of these moves: Juneteenth to Friday, June 18, Independence Day to Monday, July 5, Christmas to Friday, December 24, and New Year's Day 2028 to Friday, December 31, 2027.
Banks follow a different list. The Federal Reserve's Regulation CC, 12 CFR 229.2, defines a business day as any calendar day other than a Saturday, a Sunday and ten named holidays, and moves a holiday only when it falls on a Sunday. So Friday, July 3, 2026 is a federal holiday for OPM but a business day under that definition. The working days pages list every federal holiday by month for 2026 and 2027.
Counting business days in Excel and Google Sheets
Spreadsheets have two functions, and they count differently. Microsoft's NETWORKDAYS returns the number of whole working days between a start and an end date, and it counts both dates when they are working days: Microsoft's own example, October 1, 2012 to March 1, 2013, gives 110, which is the count with both ends included. So =NETWORKDAYS(DATE(2026,10,5),DATE(2026,10,16)) returns 10, while only 9 business days pass after October 5 up to October 16, and 8 if Columbus Day is a holiday.
To find a deadline, use WORKDAY instead, which returns the date a number of working days before or after a start date and does not count the start: =WORKDAY(DATE(2026,10,5),10) is October 19, and with a holiday range that holds October 12 it is October 20. Google Sheets has NETWORKDAYS and WORKDAY with the same arguments. In both, pass the holidays as a range of real dates, not text.
Why two counts disagree
| How it is counted | Day 10 |
|---|---|
| From the day after, weekdays only | Monday, October 19 |
| From the day after, federal holidays skipped | Tuesday, October 20 |
| Counting October 5 as day 1, weekdays only | Friday, October 16 |
| Counting October 5 as day 1, federal holidays skipped | Monday, October 19 |
Almost every disagreement comes from one of four things: whether day zero is counted, which holiday list applies (federal, state, a bank's, or a company's own), whether the weekend is Saturday and Sunday, and which time zone the last day ends in. Settle those four, write them down next to the deadline, and anyone who counts will get the same day.
The business days calculator adds or subtracts business days from the day after your start date, with your own weekend and holidays, and counts the working days between two dates with or without each end. For counts from today, the business days from today pages show the date for 1 to 120 business days with and without the federal holidays.
Questions people ask
Do business days include Saturday?
Usually not. In the United States a business day normally means Monday to Friday, and the Federal Reserve's definition for check holds starts with any calendar day other than a Saturday or a Sunday. A carrier, a store or a contract can still define its own business days, so a deadline that matters is worth checking against its own wording.
Is today counted as a business day?
For a deadline counted from today, no: today is day zero and the next working day is day one, which is how the federal courts' Rule 6 counts and how the business days calculator adds days. A count of the working days between two dates is different, and spreadsheet functions such as NETWORKDAYS include the start date when it is a working day.
How many business days are in two weeks?
Ten, when there is no holiday in the way: two runs of Monday to Friday. A federal holiday on a weekday makes it nine, so the two weeks from Monday, October 5 to Friday, October 16, 2026 hold 9 working days for anyone off on Columbus Day.
Does "3 to 5 business days" for shipping include the day I order?
Check where the seller starts counting: some estimates run from the order and some from the day the parcel is dispatched. Once you know the start, count the same way as any deadline: the day after, weekdays only, holidays skipped.
Esta guía también está en español: Cómo contar días hábiles para un plazo en EE. UU..
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