Business Day Calculator

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Business Day Calculator
Add Business Days to a DateSubtract Business Days from a DateBusiness Days Between Two Dates
Answer:
function toggleInputs(){var type=document.getElementById('calc_type').value;if(type==='between'){document.getElementById('row_days').style.display='none';document.getElementById('row_end_date').style.display='table-row';}else{document.getElementById('row_days').style.display='table-row';document.getElementById('row_end_date').style.display='none';}}function resetCalc(){setTimeout(function(){toggleInputs();document.getElementById('resultValue').innerHTML=";document.getElementById('resultLabel').innerHTML=";document.getElementById('stepsOutput').style.display='none';},10);}function isWeekend(date){var day=date.getDay();return day===0||day===6;}function calculateBusinessDays(){var type=document.getElementById('calc_type').value;var startDateStr=document.getElementById('start_date').value;var includeStart=document.getElementById('include_start').checked;var resultVal=document.getElementById('resultValue');var resultLab=document.getElementById('resultLabel');var stepsOut=document.getElementById('stepsOutput');if(!startDateStr){alert('Please select a start date');return;}var start=new Date(startDateStr+'T00:00:00′);if(type==='between'){var endDateStr=document.getElementById('end_date').value;if(!endDateStr){alert('Please select an end date');return;}var end=new Date(endDateStr+'T00:00:00′);var count=0;var current=new Date(start);var swap=false;if(start>end){var temp=start;start=end;end=temp;swap=true;}while(current<=end){if(!isWeekend(current)){if(current.getTime()===start.getTime()){if(includeStart)count++;}else{count++;}}current.setDate(current.getDate()+1);}resultLab.innerHTML='Total Business Days:';resultVal.innerHTML=count;stepsOut.innerHTML='Excluding weekends (Saturdays and Sundays). '+(swap?'(Dates were swapped for calculation)':'');stepsOut.style.display='block';}else{var numDays=parseInt(document.getElementById('num_days').value);if(isNaN(numDays)){alert('Please enter a valid number of days');return;}var current=new Date(start);var added=0;var direction=type==='add'?1:-1;if(includeStart&&!isWeekend(current)){added=1;}while(added<Math.abs(numDays)){current.setDate(current.getDate()+direction);if(!isWeekend(current)){added++;}}resultLab.innerHTML='Target Date:';resultVal.innerHTML=current.toDateString();stepsOut.innerHTML='Calculation based on a 5-day work week (Monday-Friday).';stepsOut.style.display='block';}}

Calculator Use

The Business Day Calculator is a specialized tool designed to help professionals, project managers, and logistics coordinators determine dates while excluding weekends (Saturdays and Sundays). Whether you are calculating a deadline for a legal contract, estimating a shipping arrival, or planning project milestones, this calculator provides accurate results based on a standard Monday-through-Friday work week.

This tool offers three primary modes of operation to cover all your scheduling needs:

Add Business Days
Starting from a specific date, this adds a set number of work days to find the future completion date.
Subtract Business Days
Counts backward from a deadline to find the necessary start date, skipping weekends along the way.
Days Between Two Dates
Calculates exactly how many working days exist between two specific calendar dates.

How It Works

When calculating business days, the logic differs from simple calendar math. A standard week has 7 days, but only 5 are considered "business" or "work" days. The formula essentially filters the calendar to skip Day 0 (Sunday) and Day 6 (Saturday).

Business Days = Total Days – (Saturdays + Sundays)

Our calculator uses an iterative algorithm to ensure precision:

  • Step 1: Identify the starting date and whether it should be included in the count.
  • Step 2: Move forward or backward day-by-day.
  • Step 3: Check the "Day of the Week" for each date.
  • Step 4: If the day is Monday through Friday, increment the counter.
  • Step 5: Stop when the target number of business days is reached.

Calculation Example

Example Scenario: You are signing a contract on Friday, October 6th. The terms state that you have 5 business days to provide a deposit. When is the deposit due?

Step-by-step solution:

  1. Start Date: Friday, Oct 6
  2. Day 1: Monday, Oct 9 (Skipping Sat/Sun)
  3. Day 2: Tuesday, Oct 10
  4. Day 3: Wednesday, Oct 11
  5. Day 4: Thursday, Oct 12
  6. Day 5: Friday, Oct 13
  7. Result: Your deposit is due by Friday, October 13th.

Common Questions

Does this calculator include bank holidays?

This specific calculator focuses on the standard weekend exclusion (Saturdays and Sundays). Because holidays vary significantly by country, region, and industry (e.g., Bank Holidays vs. Federal Holidays), it is recommended to subtract any specific holidays manually from the final result if they fall within your date range.

How do I count "10 Business Days" for a shipping estimate?

Typically, the day an item is shipped (the "Order Date") is NOT counted as Day 1. You would start counting the following business day. In our calculator, you would leave the "Count start date" checkbox unchecked to match this industry standard.

Why are business days important in finance?

In finance, "T+2" or "T+3" settlement cycles refer to "Trade Date plus X business days." Since stock markets and clearinghouses are closed on weekends, using a business day calculator is essential to knowing exactly when funds will clear or when a trade will be finalized.

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