Tiny ToolkitBusiness Days Calculator
Calculate working days between dates excluding weekends and public holidays. Add business days to a date for accurate project planning.
Calculate Business Days Between Dates
About Business Days Calculator
A business days calculator (also called working days calculator) helps you accurately calculate the number of working days between two dates, excluding weekends and public holidays. This is essential for project management, deadline planning, and business operations in the UK and US.
What Are Business Days?
Business days (or working days) are days when businesses typically operate. They exclude:
- Weekends: Saturdays and Sundays are excluded from business day counts
- Public Holidays: Bank holidays (UK) and federal holidays (US) are excluded
- Special Closures: Some businesses may have additional closure days
UK vs US Public Holidays
🇬🇧 UK Bank Holidays (8 per year)
- New Year's Day
- Good Friday
- Easter Monday
- Early May Bank Holiday
- Spring Bank Holiday
- Summer Bank Holiday
- Christmas Day
- Boxing Day
🇺🇸 US Federal Holidays (11 per year)
- New Year's Day
- Martin Luther King Jr. Day
- Presidents' Day
- Memorial Day
- Juneteenth
- Independence Day
- Labor Day
- Columbus Day
- Veterans Day
- Thanksgiving Day
- Christmas Day
Common Use Cases
Project Management
- Calculate project timelines excluding weekends and holidays
- Estimate delivery dates for milestones
- Plan sprint schedules and deadlines
- Track actual working days vs estimates
- Allocate resources based on available business days
Business Operations
- Calculate service level agreements (SLAs)
- Determine payment terms (e.g., Net 30 business days)
- Plan shipping and delivery schedules
- Calculate invoice due dates
- Track employee working days for payroll
Legal & Compliance
- Calculate statutory notice periods
- Determine contract deadlines
- Track legal filing deadlines
- Calculate response timeframes
- Plan court date schedules
Financial Planning
- Calculate interest accrual on business days
- Determine settlement dates for transactions
- Plan financial quarter working days
- Track trading days for investments
- Calculate payroll periods accurately
How to Use This Calculator
Calculate Between Dates Mode
- Select your holiday calendar (UK, US, or Both)
- Choose a quick preset or enter custom dates
- Enter your start date and end date
- View business days, weekends, and holidays
- See the list of public holidays in your date range
Add Business Days Mode
- Select your holiday calendar (UK, US, or Both)
- Enter your base date (starting point)
- Enter number of business days to add (positive or negative)
- View the resulting date after adding business days
- See the breakdown of days, weekends, and holidays
Business Days Calculation Examples
Example 1: Project Deadline
You need to complete a project in 20 business days starting from Monday, January 8, 2024 (UK holidays):
- Mode: Add Business Days
- Base Date: January 8, 2024
- Business Days: 20
- Result: February 5, 2024 (excludes weekends and any UK holidays)
Example 2: Invoice Payment Terms
Calculate Net 30 business days from invoice date (US holidays):
- Mode: Add Business Days
- Base Date: May 1, 2024
- Business Days: 30
- Result: June 12, 2024 (excludes Memorial Day)
Quick Reference: Working Days Per Period
Approximate business days (excluding weekends and typical holidays):
- 1 Week: ~5 business days
- 1 Month: ~20-23 business days (varies by month)
- 1 Quarter: ~63-65 business days
- 1 Year: ~250-252 business days (UK/US)
Note: Exact counts vary by year due to how holidays fall on the calendar.
Business Days vs Calendar Days
- Calendar Days: All days including weekends and holidays (30 calendar days = 30 days)
- Business Days: Only working days (30 business days ≈ 6 weeks calendar time)
- Important: Always clarify which type of days when setting deadlines
- SLAs: Service level agreements usually specify business days, not calendar days
- Contracts: Legal documents should explicitly state business vs calendar days
💡 Pro Tips
- Always specify "business days" vs "calendar days" in contracts and agreements
- Use "Add Business Days" mode to calculate accurate project deadlines
- Select the correct holiday calendar for your region (UK, US, or Both)
- Plan extra buffer time for critical deadlines near holiday periods
- Check public holiday dates when planning international projects
- Use quick presets for common time periods (month, quarter, year)
Frequently Asked Questions
What are business days?
Business days (also called working days) are weekdays (Monday-Friday) excluding public holidays. They represent days when businesses and government offices typically operate. Weekends (Saturday-Sunday) are not counted as business days.
How does this calculator exclude holidays?
Our calculator includes comprehensive UK bank holiday and US federal holiday calendars for 2024-2026. You can select UK holidays, US holidays, or both to exclude from your business day calculations.
What is the difference between calendar days and business days?
Calendar days include all days (weekdays, weekends, and holidays). Business days only count working weekdays excluding holidays. For example, 30 calendar days equals about 20-22 business days depending on weekends and holidays.
Can I add business days to a date?
Yes! Use "Add Business Days" mode to add or subtract business days from a date. Enter a base date and number of days (positive to add forward, negative to subtract backward) to find the resulting business day.
How many business days are in a year?
A typical year has approximately 250-252 business days, calculated as 365 days minus 104-105 weekend days and 8-11 public holidays (varies by country). Our calculator provides exact counts for specific date ranges.
Why use business days instead of calendar days?
Business days are crucial for accurate project planning, SLAs, payment terms, and legal deadlines. They reflect actual working time available, excluding weekends and holidays when businesses are typically closed.