How to use: Calculate business working days between dates, excluding or including weekends. Enter Start Date and End Date. Check "Include weekends as working days" to count Saturday/Sunday (useful for 24/7 operations), or uncheck to exclude them (standard Monday-Friday work week). Results show: Total Days (calendar days), Working Days (excluding weekends if unchecked), Weekend Days (Saturdays and Sundays), and Total Weeks. Used for: project timelines (30 working days = 6 weeks), delivery estimates, contract deadlines, SLA calculations, vacation planning, payroll periods, and business day counting. Standard work year: 260 working days (365 days - 104 weekend days - ~1 holiday). Critical for accurate business planning and deadline setting.