How to Count Business Days Between Two Dates
How business-day counting differs from calendar-day counting, why weekends are excluded, and where holidays fit into the calculation.
Contracts, shipping estimates, and project timelines often quote "business days" rather than calendar days — a meaningfully different number once weekends are excluded from the count.
The core calculation
Business-day counting excludes Saturdays and Sundays from the total. For a span of exactly one calendar week (7 days), that means 5 business days instead of 7 — and the gap between the two numbers grows for longer date ranges, since every full week removes 2 more days from the business-day total.
Where holidays fit in
Standard business-day math excludes weekends only — public holidays are a separate consideration that depends on your specific country, region, or company calendar, since there's no single universal holiday list. If your use case depends on excluding holidays too, subtract them manually from the weekend-adjusted total.
Why this matters for deadlines
A contract that says "30 business days" from a Friday resolves to a meaningfully later calendar date than 30 calendar days would — miscounting this is a common source of missed deadlines in shipping, legal, and payment terms.
The Date Calculator shows the business-day count alongside the total calendar days for any two dates you enter.