Business Days Calculator

A business day count classifies every calendar date in an inclusive range as a weekday or a weekend and sums the weekdays. Because the pattern repeats every seven days, the count approximates five sevenths of the span, but the exact figure depends on which weekday the range starts and ends. A common year has 260 or 261 weekdays and a leap year 260 to 262; 2024, a leap year beginning on a Monday, contains 262. Subtracting the eleven United States federal holidays leaves roughly 250 to 251 working days, the figure normally used for daily rate and project capacity calculations. Individual months range from 19 to 23 weekdays. Two limits are worth stating plainly. This count does not remove public holidays, which vary by country, state and employer, so a jurisdiction-specific result requires subtracting them by hand. It also assumes a Saturday and Sunday weekend, which is not universal: Israel observes Friday and Saturday, and the United Arab Emirates shifted to a Saturday and Sunday weekend only in January 2022. Contract language matters as much as arithmetic. Five business days from signing is normally counted from the day after the trigger event, and whether both endpoints are included changes the deadline by a day.

The weekday and weekend split that this count depends on is barely a century old. A New England mill is recorded granting Saturday off in 1908 so that Jewish workers could observe the Sabbath without losing Sunday pay, but the two day weekend spread only after Ford Motor Company adopted a five day, 40 hour week in 1926 and argued that rested workers were more productive. The Fair Labor Standards Act of 1938 made 40 hours the American overtime threshold and effectively standardised the pattern. The holiday calendar that this count deliberately ignores has its own history. Congress designated the first four federal holidays for District of Columbia workers in 1870, and the Uniform Monday Holiday Act of 1968, effective in 1971, moved Washington's Birthday, Memorial Day and Columbus Day to fixed Mondays to create long weekends. Juneteenth became the eleventh federal holiday in June 2021. In office practice the calculation was standardised by spreadsheets: the NETWORKDAYS function arrived in the Excel Analysis ToolPak add-in and became a built-in function in Excel 2007, counting weekdays inclusively between two dates with an optional list of holidays to exclude.