Business Days Calculator: Count Working Days Between Dates
Business days calculations are essential for project planning, contract deadlines, shipping estimates, and HR operations. Our Business Days Calculator counts the number of working days (Monday through Friday) between two dates, calculates a future date by adding a specific number of business days, and accounts for holidays. Whether you're planning a project timeline or calculating legal deadlines, this tool handles the complexity automatically. Use our Business Days Calculator to estimate your costs.
How Business Day Calculations Work
Business days exclude weekends (Saturday and Sunday) and optionally holidays. The calculator uses the standard 5-day work week. To count business days between two dates, it calculates the total days, subtracts weekends, and optionally subtracts holidays. To add business days to a date, it skips weekend days and holidays.
Different countries and organizations observe different holidays. The calculator includes pre-loaded holiday sets for the US (federal holidays), UK, Canada, Australia, and India. You can also add custom holidays for your specific needs.
Using the Business Days Calculator
Select the mode: count business days between two dates, or add business days to a start date. Enter the dates and the number of business days (for addition mode). Choose your country or region for holiday inclusion. The calculator shows the result, a breakdown of weekends and holidays excluded, and a calendar view.
For project planning, enter a start date and the number of business days needed. The calculator shows the projected completion date. Perfect for estimating when work will be done considering only working days.
Common Use Cases
Legal and Contract Deadlines
Many legal documents specify business days for response times. A 30-business-day response period starting on December 15 might extend into late January due to holidays — our calculator handles this accurately.
Shipping and Delivery Estimates
E-commerce shipping estimates typically use business days. 5-7 business days for standard shipping means excluding weekends. An order placed on Friday with 5 business day shipping arrives the following Friday.
Project Management
Task durations in project plans are usually measured in business days. A task estimated at 10 business days starting Tuesday June 1 completes on Tuesday June 15 (excluding weekends).
Payroll and HR
Pay periods, PTO accrual, and notice periods are often calculated in business days. Two weeks notice is typically 10 business days. The calculator ensures accurate end dates.
Holiday Sets Available
- US Federal Holidays: New Year's Day, MLK Day, Presidents Day, Memorial Day, Juneteenth, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving, Christmas
- UK Bank Holidays: New Year's Day, Good Friday, Easter Monday, Early May Bank Holiday, Spring Bank Holiday, Summer Bank Holiday, Christmas Day, Boxing Day
- Canada Statutory Holidays: New Year's Day, Family Day, Good Friday, Victoria Day, Canada Day, Civic Holiday, Labour Day, Thanksgiving, Remembrance Day, Christmas, Boxing Day
- Australia Public Holidays: New Year's Day, Australia Day, Good Friday, Easter Monday, ANZAC Day, Queen's Birthday, Labour Day, Christmas, Boxing Day
- India Public Holidays: Republic Day, Holi, Independence Day, Gandhi Jayanti, Diwali, Dussehra, Christmas, plus state-specific holidays
Real-World Example
A contract signed on December 20, 2025 requires a response within 15 business days, excluding US federal holidays:
- Start date: December 20, 2025 (Saturday, so next business day is Monday December 22)
- 15 business days from December 22:
- Exclude weekends: December 27-28, January 3-4, January 10-11
- Exclude holidays: January 1 (New Year's Day)
- Completion date: January 14, 2026
- Calendar elapsed: 25 calendar days to get 15 business days
Without the holiday and weekend awareness, one might incorrectly estimate January 9 as the deadline — missing by 5 days.
Worked Example: Tracing the Calculator's Math
In count mode, enter January 1, 2026 as the start and January 31, 2026 as the end. The tool iterates day by day and tallies every Monday through Friday, reporting 23 business days. It also reports the total calendar span including both endpoints as 31 days, and derives 8 weekend days as the difference (31 minus 23). Because the start date January 1 is a Thursday and the end date January 31 falls on a Saturday, the weekend count includes that final Saturday — the tool counts both the start and end dates themselves in the calendar-day total.
The two numbers to compare are the business-day count and the calendar-day count, because their gap tells you how much weekend padding sits inside any deadline. January 1 to January 31 produces a 23-business-day window that stretches 31 calendar days — weekend padding of 8 days, or about 26% of the total window. A 10-business-day project starting the same January 1, by contrast, lands on January 15 (a Thursday): just 14 calendar days, because that short span contains only two weekend breaks.
In add mode, the tool simply skips Saturdays and Sundays while counting forward. Starting from January 1, 2026 and adding 10 business days steps over the weekends of January 3–4 and January 10–11, and the result tile displays January 15, 2026 as a formatted date rather than a day count. If your deadline falls near a public holiday like New Year's Day, remember that this calculator counts Monday–Friday working days and does not subtract holidays automatically, so you may need to add extra days manually for holiday closures.
Start Calculating
Use our Business Days Calculator below to compute working days accurately for any business need. Also check our Date Difference Calculator for total days between dates and our Weekday Calculator for finding the day of the week for any date.
Related Calculators
Use our Business Days Calculator Guide together with related tools such as Age Calculator, Anniversary Calculator, Business Days Calculator to plan more accurately. Each calculator runs instantly in your browser with step-by-step guidance.
Written by the CalcMaster Pro Editorial Team — financial, health, and DIY tools reviewed for accuracy. All calculators run on standard, widely accepted formulas. Always confirm final numbers with a qualified professional for decisions that require official figures.