Jquery and Javascript date calculation /Weekdays calculation.

Jquery and Javascript date calculation /Weekdays calculation.
Open sharepoint page in edit mode.
Add content editor webpart to page at the end.
Add below script to content editor webpart.

// JScript source code
<script type="text/javascript" src="http://code.jquery.com/jquery.min.js">script>
<script src='/_layouts/SP.js' type='text/javascript'>script>
<script type=""text/javascript"">
    var myItems;
    var countHolidays = 0;
 
    $("input[name='CONTROL_NAME$DateTimeField$DateTimeFieldDate']").focusout(function () {
 
        var dtfrom = $("input[name='CONTROL_NAME$DateTimeField$DateTimeFieldDate']").val();
 
        var dtto = $("input[name='CONTROL_NAME$DateTimeField$DateTimeFieldDate']").val();
 
        if (dtfrom.length > 0 && dtto.length > 0) {
            var DaysDiff;
            var bussDays = calcBusinessDays(new Date(dtfrom), new Date(dtto));
            GetHolidays(dtfrom, dtto);
 
            DaysDiff = bussDays - countHolidays;
 
            $("#ctlCONTROL_ID_TextField").val(DaysDiff);
        }
 
    });
 
    function calcBusinessDays(dDate1, dDate2) { // input given as Date objects
        var iWeeks, iDateDiff, iAdjust = 0;
        if (dDate2 < dDate1) return -1; // error code if dates transposed
        var iWeekday1 = dDate1.getDay(); // day of week
        var iWeekday2 = dDate2.getDay();
        iWeekday1 = (iWeekday1 == 0) ? 7 : iWeekday1; // change Sunday from 0 to 7
        iWeekday2 = (iWeekday2 == 0) ? 7 : iWeekday2;
        if ((iWeekday1 > 5) && (iWeekday2 > 5)) iAdjust = 1; // adjustment if both days on weekend
        iWeekday1 = (iWeekday1 > 5) ? 5 : iWeekday1; // only count weekdays
        iWeekday2 = (iWeekday2 > 5) ? 5 : iWeekday2;
 
        iWeeks = Math.floor((dDate2.getTime() - dDate1.getTime()) / 604800000);
 
        if (iWeekday1 <= iWeekday2) {
            iDateDiff = (iWeeks * 5) + (iWeekday2 - iWeekday1);
        } else {
            iDateDiff = ((iWeeks + 1) * 5) - (iWeekday1 - iWeekday2);
        }
 
        iDateDiff -= iAdjust; // take into account both days on weekend
 
        return (iDateDiff + 1); // add 1 because dates are inclusive
    }
 
 
    // this function will find date difference in days.
    function daydiff(first, second) {
        var start = new Date(first);
        var end = new Date(second);
        var diff = new Date(end - start);
        return (diff) / (1000 * 60 * 60 * 24)
    }
 
 
    function GetHolidays(fromdate, todate) {
        var myQueryString = '' + todate + '' + fromdate + '';
 
        var myContext = new SP.ClientContext.get_current();
        var myWeb = myContext.get_web();
        var myList = myWeb.get_lists().getByTitle('Holidays');
        var myQuery = new SP.CamlQuery();
        myQuery.set_viewXml(myQueryString);
        myItems = myList.getItems(myQuery);
        myContext.load(myItems, 'Include(ID, Title, Date, Year)');
        myContext.executeQueryAsync(Function.createDelegate(
                                this, GetHolidaysSuccess),
                     Function.createDelegate(
                                this, GetHolidaysFail));
    }
 
    function GetHolidaysFail(sender, args) {
        //alert('GetEmployeesByAge() failed:' + args.get_message());
        //return false;
    }
 
    function GetHolidaysSuccess(sender, args) {
        var HolidaysCount = myItems.get_count();
 
        var currYear = (new Date).getFullYear();
 
        var holidaysEnumerator = myItems.getEnumerator();
        var holidaysDetails = '';
 
 
 
        // Loop through all items
        while (holidaysEnumerator.moveNext()) {
            // Get current item
            var currentHoliday = holidaysEnumerator.get_current();
            if (currentHoliday.get_item("Year") == currYear) {
                countHolidays = countHolidays + 1;
            }
        }
    }
script>