Whether you're counting a 30-day notice period, calculating a contract deadline, or planning a project timeline, getting business days right matters. A simple mistake — like forgetting to exclude a public holiday — can mean a missed deadline, a legal penalty, or an unhappy client.
This guide covers everything you need to know about calculating business days, with practical examples and a free tool to do the math for you.
What Is a Business Day?
A business day (also called a working day) is any day that is not a weekend (Saturday or Sunday) and not a public holiday. In most countries, business days run Monday through Friday, excluding national holidays.
The exact holidays depend on your country. The United States has 11 federal holidays, the UK has 8 bank holidays, and Australia has 8 national public holidays (plus state-specific ones).
How to Count Business Days: Step by Step
- Identify your start and end dates — Know whether the start date itself counts (some contracts say "from" vs "after" a date).
- Exclude weekends — Remove all Saturdays and Sundays from your count.
- Exclude public holidays — Remove any national or bank holidays that fall on weekdays.
- Count what's left — The remaining weekdays are your business days.
Skip the manual counting
Our free calculator does this instantly for 50+ countries, with accurate holiday calendars.
Open Business Days Calculator →Common Mistakes to Avoid
- Confusing calendar days with business days — "30 days" in a contract usually means 30 calendar days, but "30 business days" means about 6 weeks of calendar time.
- Forgetting country-specific holidays — If you're working with international clients, their holidays are different from yours.
- Not checking if start/end date is included — Legal contracts often specify "within 5 business days of receipt" — does the day of receipt count?
- Ignoring state/regional holidays — Some countries (US, Australia, Canada) have state-level holidays in addition to national ones.
Business Days by Month (2026)
Here's a quick reference for the United States:
- January 2026 — 21 business days
- February 2026 — 19 business days
- March 2026 — 22 business days
- April 2026 — 22 business days
- May 2026 — 20 business days
- June 2026 — 21 business days
- July 2026 — 22 business days
- August 2026 — 21 business days
- September 2026 — 21 business days
- October 2026 — 21 business days
- November 2026 — 18 business days
- December 2026 — 22 business days
Counts vary by country — use the calculator to check your specific location.
When Business Days Matter Most
Contracts & Legal
Most legal deadlines — notice periods, response windows, filing deadlines — are counted in business days. Missing one by even a single day can have serious consequences. Always verify whether a contract specifies "business days" or "calendar days."
HR & Payroll
Probation periods, notice periods, leave accrual, and payroll processing all depend on accurate business day counts. A 90-day probation period in business days is actually about 4.5 months of calendar time.
Project Management
Setting realistic deadlines means knowing exactly how many working days you have. A "2-week deadline" over the Christmas holiday period might give you only 6-7 actual working days.
Shipping & Logistics
"Ships within 5 business days" means you need to exclude weekends and holidays. International shipping also needs to account for the recipient country's holidays.