What Are Business Days and How Do You Count Them?
Business days exclude weekends and public holidays, but counting them correctly requires knowing which holidays apply and how to handle partial days. This post explains what counts as a business day and how to count them accurately.
The Basic Definition of a Business Day
A business day is any day when normal commercial and government operations occur. In most countries with a Monday-through-Friday work week, business days run from Monday to Friday and exclude Saturday and Sunday. A five-day work week means there are approximately 21 to 23 business days in a typical month.
The term working day is often used interchangeably with business day, though some industries draw a distinction based on operational hours. A bank, for example, might process transactions only during specific hours on business days, while a manufacturing facility might define working days differently based on shift schedules.
Public holidays further reduce the count of business days in any given period. When a holiday falls on a weekend, many employers and government offices observe it on the nearest Monday or Friday, creating an additional non-business day in that week.
How Public Holidays Affect Business Day Counts
Every country, and often every region within a country, has its own set of public holidays. In the United States, federal holidays include days like New Year's Day, Memorial Day, Independence Day, Thanksgiving, and Christmas. When these fall on a Saturday, the Friday before is the observed holiday. When they fall on a Sunday, the following Monday is observed.
Shipping and delivery services use business day calculations extensively. When a retailer says an order ships in three to five business days, they are counting forward from the ship date while skipping weekends and any holidays that fall within that window.
Legal and financial deadlines also rely on business day counts. A contract might give a party 10 business days to respond to a notice. If the notice arrives on Wednesday before Thanksgiving week, you need to skip Thursday (Thanksgiving) and count only Monday through Wednesday of each subsequent week until you reach 10 qualifying days.
Manual Method for Counting Business Days
To count business days manually, start at the first day after your start date and mark each weekday (Monday through Friday) as a business day. Skip any Saturdays, Sundays, and public holidays you encounter. Continue until you have counted the required number of business days, and the final day you land on is your end date.
Going the other direction, if you need to count how many business days fall between two dates, list all calendar days in that range, remove weekends, and then remove any public holidays. The remaining count is your business day total.
Spreadsheet applications like Excel and Google Sheets include a NETWORKDAYS function that automates this calculation. You provide a start date, an end date, and optionally a list of holidays, and the function returns the number of business days in that range.
Regional and Industry Variations
Not all business calendars follow the Monday-through-Friday standard. In many Middle Eastern countries, the work week runs Sunday through Thursday, with Friday and Saturday as the weekend. Financial markets in these regions observe different non-trading days than Western exchanges.
The banking industry has its own concept of banking days, which can differ from general business days. Federal Reserve holidays in the United States determine when interbank transfers can be processed, and these dates affect when funds clear even if a business is otherwise open.
International transactions must account for business day calendars in multiple jurisdictions. A contract between a US company and a European company might specify which country's holiday calendar takes precedence, or it might count only days that are business days in both locations.
Using an Online Calculator
Online business day calculators simplify the process by automatically accounting for weekends and allowing you to input specific holidays for your region. You enter a start date and either a number of business days to add or an end date to count toward, and the calculator handles all the exceptions.
The most accurate calculators let you specify your country or region so they can apply the correct public holiday schedule. Some also let you customize the holiday list for situations where your industry observes additional non-business days beyond standard public holidays.
For recurring calculations, such as determining deadlines for a project with multiple milestones, building the business day logic into a spreadsheet or project management tool is more reliable than counting manually each time. One missed holiday can shift all subsequent deadlines by a day.