Business days are weekdays (Monday through Friday) excluding public holidays. Calendar days include every day—weekends and holidays too.
This distinction matters for contracts, shipping estimates, legal deadlines, and payment terms.
How Business Days Are Counted
When something is due "within 5 business days," only working days count:
- If you start counting on Monday, day 5 is the following Monday
- Weekends (Saturday and Sunday) are skipped
- Public holidays are typically skipped too
Use our Business Days Calculator to count business days between any two dates or find a date X business days away.
When Each Type Is Used
Business days are common for:
- Bank processing times
- Shipping and delivery estimates
- Legal response periods
- Invoice payment terms
Calendar days are used for:
- Rental agreements
- Subscription billing cycles
- Age calculations
- Medical waiting periods
Holiday Complications
Which holidays count as non-business days depends on:
- Country: US, UK, Canada, and Australia have different public holidays
- Industry: Banks may close on days retail stores don't
- Contract terms: Some agreements specify which holidays apply
The "Start Day" Question
Another common confusion: does the count start on day 0 or day 1?
- Most legal contexts start counting the day after the triggering event
- Some contracts count the event day as day 1
- Always check the specific terms or jurisdiction
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