Business Days Calculator

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Business Days Calculator
Count Business Days Between DatesAdd Business Days to a DateSubtract Business Days from a Date
Result:
Business Days: —
function toggleInputs(){var mode=document.getElementById('calc_type').value;if(mode==='count'){document.getElementById('rowEndDate').style.display='table-row';document.getElementById('rowDays').style.display='none';}else{document.getElementById('rowEndDate').style.display='none';document.getElementById('rowDays').style.display='table-row';}}function resetCalc(){setTimeout(function(){toggleInputs();document.getElementById('resultValue').innerHTML='—';},10);}function calculateResult(){var type=document.getElementById('calc_type').value;var startInput=document.getElementById('startDate').value;var holidayCount=parseInt(document.getElementById('holidays').value)||0;var includeStart=document.getElementById('includeStart').checked;if(!startInput){alert('Please select a start date');return;}var startDate=new Date(startInput);startDate.setHours(0,0,0,0);if(type==='count'){var endInput=document.getElementById('endDate').value;if(!endInput){alert('Please select an end date');return;}var endDate=new Date(endInput);endDate.setHours(0,0,0,0);var count=0;var curDate=new Date(startDate);if(!includeStart){curDate.setDate(curDate.getDate()+1);}while(curDate<=endDate){var day=curDate.getDay();if(day!==0&&day!==6){count++;}curDate.setDate(curDate.getDate()+1);}var finalResult=count-holidayCount;document.getElementById('resultLabel').innerHTML='Total Business Days:';document.getElementById('resultValue').innerHTML=finalResult=0?1:-1;var absoluteTarget=Math.abs(target);if(absoluteTarget>0){while(added0){var hAdded=0;while(hAdded<holidayCount){finalDate.setDate(finalDate.getDate()+direction);var day=finalDate.getDay();if(day!==0&&day!==6){hAdded++;}}}document.getElementById('resultLabel').innerHTML='Target Date:';document.getElementById('resultValue').innerHTML=finalDate.toDateString();}}

Using the Business Days Calculator

A business days calculator is an essential tool for professionals, project managers, and logistics coordinators who need to plan schedules based on the standard working week. Unlike a standard calendar that counts every 24-hour period, this calculator specifically isolates Monday through Friday, automatically excluding Saturdays and Sundays.

Whether you are calculating a shipping window, a contractual deadline, or a payroll cycle, understanding the gap between "calendar days" and "business days" is vital for accuracy. This tool allows you to perform three primary functions:

  • Count the number of working days between two specific dates.
  • Add a set number of business days to a starting date to find a future deadline.
  • Subtract business days from a date to determine when a project should have started.

How the Calculation Works

The logic behind a business days calculator follows a simple yet rigorous algorithm. The standard definition of a business day includes Monday, Tuesday, Wednesday, Thursday, and Friday. Weekends (Saturday and Sunday) are excluded.

Business Days = (Total Calendar Days) – (Saturdays + Sundays) – (Public Holidays)

Our calculator allows you to manually input the number of public holidays. This is necessary because bank holidays and national observations vary significantly by country, state, and industry. For example, a "Bank Holiday" in the UK may not be a holiday in the United States.

Step-by-Step Calculation Example

Scenario: You are managing a construction project that starts on October 1st. The contract specifies that you have 15 business days to complete the first phase. There is one national holiday during this period.

Manual Calculation:

  1. Start Date: October 1st (Assuming it's a Monday).
  2. Week 1: Oct 1 (Mon) to Oct 5 (Fri) = 5 Business Days.
  3. Weekend: Oct 6-7 (Excluded).
  4. Week 2: Oct 8 (Mon) to Oct 12 (Fri) = 5 Business Days (Total 10).
  5. Weekend: Oct 13-14 (Excluded).
  6. Week 3: Oct 15 (Mon) to Oct 19 (Fri) = 5 Business Days (Total 15).
  7. Holiday Adjustment: Since there is 1 holiday, we must add one more business day to compensate.
  8. Final Result: The phase must be completed by Monday, October 22nd.

Common Questions (FAQ)

Does the calculator include the start date?

By default, many business calculations start "the day after." However, our business days calculator includes a checkbox option to "Include Start Date." If you check this, the start date counts as Day 1 if it falls on a weekday.

How does it handle Leap Years?

The JavaScript engine powering this calculator automatically accounts for leap years. February 29th will be counted as a business day if it falls on a Monday through Friday.

Why are holidays not automatic?

Holidays are highly localized. While Christmas is almost universal, dates like Thanksgiving (US), Boxing Day (UK/Canada), or Diwali (India) occur on different dates or are only observed in specific regions. By allowing a manual "Exclude Public Holidays" input, we ensure the business days calculator is accurate for users worldwide.

Is Saturday considered a business day?

In the standard international business model, Saturday is not a business day. However, in some industries like retail or certain Middle Eastern countries where the weekend falls on Friday/Saturday, the definition changes. This calculator currently follows the Mon-Fri standard.

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