What Are Calendar Days?
Calendar days include every consecutive 24-hour day from Monday through Sunday, without omitting weekends, official holidays, or company closures. Every year contains 365 calendar days (or 366 in leap years).
What Are Business Days?
Business days refer exclusively to official working days. In the United States, Europe, and most international markets, business days typically span Monday through Friday, excluding Saturday, Sunday, and statutory public holidays.
Contractual Implications
If an agreement specifies a "30-day notice period", it typically implies 30 calendar days unless explicitly labeled as "30 business days". A 30 business day deadline can actually encompass 6 full calendar weeks (approx. 42 to 44 calendar days). Always confirm which terminology applies to prevent legal misunderstandings.