A business day (also called a working day) is any day that is not a Saturday, Sunday, or public holiday. In most countries, business days are Monday through Friday. However, public holiday calendars vary by country, region, and industry. The US has 10 federal holidays; the UK has 8 bank holidays in England and Wales; Canada has varying provincial holidays on top of federal ones. Financial and legal contracts often specify which country's business days apply.
Business day calculations matter for contract deadlines, payment terms, shipping estimates, and legal notice periods. A 5-business-day delivery from Friday ships Friday, skips Saturday and Sunday, then counts Monday–Friday of the following week — arriving the next Friday. Net-30 payment terms count 30 calendar days, not business days. Always clarify when precision matters.
Business Day Calculation Examples
Start Date
Add Business Days
Result (US holidays excluded)
Monday
5 BD
Next Monday
Friday
5 BD
Friday + 1 week
Thursday before long weekend
5 BD
Wednesday the following week
Month-end Friday
10 BD
2 weeks + 2 days
Business Days vs. Calendar Days in Contracts and Logistics
Business days (also called working days) exclude weekends and public holidays, making them essential in legal contracts, banking, shipping, and employment law. A payment due “within 5 business days” may span 7 or more calendar days if weekends or holidays fall within the period. Banking regulations specify settlement periods (e.g., T+2 settlement for stock trades) in business days. Shipping carriers quote transit times in business days; a 3-business-day shipment placed on a Friday afternoon typically arrives the following Wednesday, not Monday. Employment law in many jurisdictions defines notice periods, appeal windows, and response deadlines in business days. Internationally, public holidays differ by country, so a business-day calculation between parties in different countries requires knowing which country’s calendar applies. Automated date calculation handles these complexities, but understanding the underlying logic is essential for contract negotiation, deadline tracking, and project scheduling.
