Calculate working days between two dates in Javascript excepts holidays

Question

I have a javascript function which is calculating working days between 2 dates, it works, but the problem is that it not consider holidays. How can I modify this function, for example by adding holidays in exception array?

Searched in internet about this question, but haven't find about holidays exception.

For example holidays array:

var holidays = ['2016-05-03','2016-05-05'];

And I have a functions to calculate this:

function workingDaysBetweenDates(d0, d1) {
    var startDate = parseDate(d0);
    var endDate = parseDate(d1);  
    // Validate input
    if (endDate < startDate)
        return 0;

    // Calculate days between dates
    var millisecondsPerDay = 86400 * 1000; // Day in milliseconds
    startDate.setHours(0,0,0,1);  // Start just after midnight
    endDate.setHours(23,59,59,999);  // End just before midnight
    var diff = endDate - startDate;  // Milliseconds between datetime objects    
    var days = Math.ceil(diff / millisecondsPerDay);

    // Subtract two weekend days for every week in between
    var weeks = Math.floor(days / 7);
    days = days - (weeks * 2);

    // Handle special cases
    var startDay = startDate.getDay();
    var endDay = endDate.getDay();

    // Remove weekend not previously removed.   
    if (startDay - endDay > 1)         
        days = days - 2;      

    // Remove start day if span starts on Sunday but ends before Saturday
    if (startDay == 0 && endDay != 6)
        days = days - 1  

    // Remove end day if span ends on Saturday but starts after Sunday
    if (endDay == 6 && startDay != 0)
        days = days - 1  

    return days;
}
function parseDate(input) {
    // Transform date from text to date
  var parts = input.match(/(\d+)/g);
  // new Date(year, month [, date [, hours[, minutes[, seconds[, ms]]]]])
  return new Date(parts[0], parts[1]-1, parts[2]); // months are 0-based
}

Have made an example in jsfiddle:

JSFiddle example

Maybe there are some other functions which can easy use in Jquery?

Answer 1

Try:

var startDate = new Date('05/03/2016');
var endDate = new Date('05/10/2016');
var numOfDates = getBusinessDatesCount(startDate,endDate);

function getBusinessDatesCount(startDate, endDate) {
    let count = 0;
    const curDate = new Date(startDate.getTime());
    while (curDate <= endDate) {
        const dayOfWeek = curDate.getDay();
        if(dayOfWeek !== 0 && dayOfWeek !== 6) count++;
        curDate.setDate(curDate.getDate() + 1);
    }
    alert(count);
    return count;
}

Answer 2

The easiest way to achieve it is looking for these days between your begin and end date.

Edit: I added an additional verification to make sure that only working days from holidays array are subtracted.

$(document).ready(() => {
  $('#calc').click(() => {
  var d1 = $('#d1').val();
  var d2 = $('#d2').val();
    $('#dif').text(workingDaysBetweenDates(d1,d2));
  });
});

let workingDaysBetweenDates = (d0, d1) => {
  /* Two working days and an sunday (not working day) */
  var holidays = ['2016-05-03', '2016-05-05', '2016-05-07'];
  var startDate = parseDate(d0);
  var endDate = parseDate(d1);  

// Validate input
  if (endDate <= startDate) {
    return 0;
  }

// Calculate days between dates
  var millisecondsPerDay = 86400 * 1000; // Day in milliseconds
  startDate.setHours(0, 0, 0, 1);  // Start just after midnight
  endDate.setHours(23, 59, 59, 999);  // End just before midnight
  var diff = endDate - startDate;  // Milliseconds between datetime objects    
  var days = Math.ceil(diff / millisecondsPerDay);

  // Subtract two weekend days for every week in between
  var weeks = Math.floor(days / 7);
  days -= weeks * 2;

  // Handle special cases
  var startDay = startDate.getDay();
  var endDay = endDate.getDay();
    
  // Remove weekend not previously removed.   
  if (startDay - endDay > 1) {
    days -= 2;
  }
  // Remove start day if span starts on Sunday but ends before Saturday
  if (startDay == 0 && endDay != 6) {
    days--;  
  }
  // Remove end day if span ends on Saturday but starts after Sunday
  if (endDay == 6 && startDay != 0) {
    days--;
  }
  /* Here is the code */
  holidays.forEach(day => {
    if ((day >= d0) && (day <= d1)) {
      /* If it is not saturday (6) or sunday (0), substract it */
      if ((parseDate(day).getDay() % 6) != 0) {
        days--;
      }
    }
  });
  return days;
}
           
function parseDate(input) {
    // Transform date from text to date
  var parts = input.match(/(\d+)/g);
  // new Date(year, month [, date [, hours[, minutes[, seconds[, ms]]]]])
  return new Date(parts[0], parts[1]-1, parts[2]); // months are 0-based
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" id="d1" value="2016-05-02"><br>
<input type="text" id="d2" value="2016-05-08">

<p>Working days count: <span id="dif"></span></p>
<button id="calc">Calc</button>

<p>
Now it shows 5 days, but I need for example add holidays 
3 and 5 May (2016-05-03 and 2016-05-05) so the result will be 3 working days
</p>