How to Use the Business Days Calculator
The calculator has two modes. Business Days Between Dates counts the working days from a start date to an end date, inclusive of both. Add / Subtract Business Days works out a future or previous date by moving a set number of business days from a starting date. In both modes you can add your own holiday dates to exclude them from the count.
How Business Days Are Calculated
For this calculator, a business day means a Monday-to-Friday weekday. Saturday and Sunday are excluded by default. If you add holiday dates, any that fall on a weekday are also removed from the total. The calculator walks through each calendar date in the range individually, so month lengths, leap years and year boundaries are all handled correctly.
Business Days Between Two Dates
The between-dates mode counts inclusively: both the start and end dates are counted when they are working days. Monday to Friday of the same week is 5 business days. A single date counted against itself is 1 business day if it is a weekday, or 0 if it falls on a weekend. The result always states that the count is inclusive so there is no ambiguity.
Business Days vs Calendar Days
Calendar days include every date in the range, weekends included. Business days exclude configured weekend days and any selected holidays. A two-week span is 14 calendar days but typically only 10 business days. For the total calendar-day difference between two dates, use the Days Between Dates Calculator.
How to Add Business Days to a Date
In Add / Subtract mode, counting starts after the starting date — the starting date itself is not counted. Starting on a Monday, +1 business day is Tuesday. Starting on a Friday, +1 business day is the following Monday. Starting on a Monday, +5 business days is the following Monday, because the five working days are Tuesday, Wednesday, Thursday, Friday and the next Monday.
How to Subtract Business Days from a Date
Subtraction works the same way in reverse. Counting starts from the day before the starting date and moves backwards, skipping weekends and holidays. Monday − 1 business day is the previous Friday. Friday − 1 business day is Thursday.
Weekends and Business Days
This calculator uses Saturday and Sunday as the default weekend, which is the most common convention. Weekend definitions are not universal worldwide — some regions observe a Friday–Saturday or Sunday–Monday weekend — so if your situation uses a different pattern, adjust your expectations accordingly.
Holidays and Business Days
Tick "Exclude holidays" and add the specific dates you want to skip. Holidays vary by country, region and organisation, and this calculator does not assume any particular jurisdiction's public holidays — you enter the dates that apply to you. A holiday that falls on a weekend is not double-counted: it is already removed by the weekend exclusion, so it does not reduce the business-day total a second time.
Business Days Calculator vs Days Between Dates Calculator
The Days Between Dates Calculator measures the total calendar-day difference between two dates, including weekends. This Business Days Calculator counts only working weekdays after excluding weekends and any selected holidays. Use the first for elapsed calendar time and this one for working-day counts.
Common Business Day Calculation Mistakes
- Counting weekends as business days. Saturday and Sunday are not business days, so a Monday-to-Friday week is 5, not 7.
- Double-counting holidays that fall on weekends. A holiday on a Saturday is already excluded by the weekend rule, so it must not be subtracted again.
- Including the starting date when adding business days. Monday + 1 business day is Tuesday, not Monday — counting starts the next day.
- Forgetting month and year boundaries. Business-day counts cross month and year edges one calendar date at a time, so there is no rounding error.
- Assuming public holidays are universal. Public holidays differ by country, region and employer, so enter the dates that apply to your situation.
- Using elapsed hours instead of calendar dates. Daylight saving can shift a timestamp by an hour; this calculator works with whole calendar dates in UTC to avoid that.
FAQs
- What is a business day?
- A business day is a working day — normally Monday through Friday, excluding weekends and any non-working holidays. This calculator treats Saturday and Sunday as weekends by default and counts the remaining weekdays as business days.
- How do I calculate business days between two dates?
- Use the "Business Days Between Dates" mode, enter a start date and an end date, and the calculator counts every weekday in the range inclusively. Weekends are excluded by default, and any holiday dates you add are also removed from the total.
- Are weekends included in business days?
- No. Business days exclude weekends. This calculator uses Saturday and Sunday as the default weekend, so only Monday through Friday are counted as business days unless you turn off weekend exclusion.
- Does the calculator include the start and end dates?
- Yes — the "Business Days Between Dates" mode counts inclusively, so both the start and end dates are counted when they are working days. Monday to Friday of the same week is 5 business days, and a single date counted against itself is 1 business day (or 0 if it falls on a weekend).
- How do I add business days to a date?
- Use the "Add / Subtract Business Days" mode, choose Add, enter a starting date and a number of business days. Counting starts from the day after the starting date, so Monday + 1 business day is Tuesday and Friday + 1 business day is the following Monday.
- What date is 5 business days from today?
- Enter today as the starting date, choose Add, and enter 5. Counting starts the day after today and skips weekends and any holidays you have added, so 5 business days from a Monday lands on the following Monday.
- How do I subtract business days from a date?
- Choose Subtract instead of Add and enter the number of business days. Counting starts from the day before the starting date and moves backwards, skipping weekends and holidays. Monday − 1 business day is the previous Friday.
- Can I exclude holidays?
- Yes. Tick "Exclude holidays" and add the specific dates you want to skip. The calculator does not automatically know your country or organisation's public holidays, because those vary by jurisdiction — enter the dates that apply to you.
- What happens if a holiday falls on a weekend?
- It is not double-counted. When weekends are excluded, a holiday that lands on a Saturday or Sunday is already removed by the weekend count, so it does not reduce the business-day total a second time. Only holidays that fall on a weekday are subtracted from the total.
- Are business days always Monday to Friday?
- For this calculator, yes — the default weekend is Saturday and Sunday, so business days are Monday through Friday. This is the most common convention, but weekend definitions vary around the world, so check the rules that apply to your situation if you are unsure.