Business Days Calculator

Business days, also called working days or weekdays, are calendar days that fall on Monday through Friday and are not designated public holidays. They represent the days on which most commercial, financial, legal, and governmental institutions operate. The concept is fundamental to contract law, project management, banking, and any scheduling that depends on institutional operating hours.

Counting business days between two dates matters because calendar days and working days can diverge significantly. A 10-calendar-day window starting on a Thursday might contain only 6 or 7 business days once weekends are excluded, and fewer still if public holidays fall within the range. This distinction is critical for legal deadlines (court filings, response periods), banking transactions (wire transfer settlement, check clearing), and project timelines (delivery commitments, sprint planning).

This calculator counts the business days between two dates by iterating through each calendar day and excluding Saturdays, Sundays, and optionally a set of US federal public holidays. A custom holiday input field allows you to add additional local holidays (state holidays, company-specific days, or international public holidays) as comma-separated dates in YYYY-MM-DD format.

The result includes total calendar days, the number of weekends, the number of holidays, and the net business days — a complete breakdown that is useful for both planning and retrospective analysis of a project or deadline window.

The calculator iterates from the start date to the end date inclusively, checking each day's day-of-week number. Day 0 is Sunday, Day 6 is Saturday — any day with a day number of 1 through 5 (Monday-Friday) that is not in the holiday set counts as a business day.

When the holiday exclusion option is enabled, this calculator automatically includes the standard US federal public holidays for each year in the date range. The 11 US federal holidays are: New Year's Day (January 1), Martin Luther King Jr. Day (third Monday in January), Presidents' Day (third Monday in February), Memorial Day (last Monday in May), Juneteenth National Independence Day (June 19), Independence Day (July 4), Labor Day (first Monday in September), Columbus Day (second Monday in October), Veterans Day (November 11), Thanksgiving Day (fourth Thursday in November), and Christmas Day (December 25).

When a federal holiday falls on a Saturday, it is typically observed on the preceding Friday. When it falls on a Sunday, it is observed on the following Monday. This calculator uses the actual calendar date of each holiday rather than the observed date, which may differ slightly from what your employer or bank considers a non-business day. For maximum accuracy with your specific organization's schedule, use the custom holidays field to enter the exact dates your institution observes.

Legal instruments commonly specify deadlines in business days rather than calendar days precisely because weekends and holidays are not working days. A contract requiring a response within "5 business days" gives the responding party longer than 5 calendar days if the period spans a weekend. Courts and arbitration rules typically publish specific definitions of what constitutes a business day in their jurisdiction, sometimes including Saturday as a half-day or specifying that federal holidays apply regardless of which party's state celebrates them.

In banking and finance, business days govern settlement windows. Stock trades typically settle T+2 (two business days after the trade date). International wire transfers require 1-5 business days. Mortgage closing timelines are expressed in business days, as are right-of-rescission periods. Understanding exactly how many business days separate two dates is therefore a matter of financial and legal precision, not merely scheduling convenience.

A related but distinct operation is finding the date that falls exactly N business days after a starting date. This is useful for calculating when a payment will clear, when a legal response deadline falls, or when a project phase will complete. While this calculator measures business days between two known dates, the Date Add/Subtract calculator can be combined with business day rules for forward projection.

The formula for adding N business days is: start from the start date, advance one day at a time, and count only Monday-Friday non-holiday days toward N. If you need to add 10 business days to a Wednesday and that period includes a holiday on a Monday, the result will be 13 calendar days later rather than the expected 14 (2 weekend days + 10 weekdays - 1 holiday absorbed into the weekend correction count).