$(function () {
    $("#from").datepicker({
        defaultDate: "+1w",
        changeMonth: true,
        numberOfMonths: 3,
        onClose: function (selectedDate) {
            $("#to").datepicker("option", "minDate", selectedDate);
        }
    });
    $("#to").datepicker({
        defaultDate: "+1w",
        changeMonth: true,
        numberOfMonths: 3,
        onClose: function (selectedDate) {
            $("#from").datepicker("option", "maxDate", selectedDate);
        }
    });
});

$("#to").change(function () {
    var final = $("#to").datepicker("getDate");
    var start = $("#from").datepicker("getDate");
    var days = new Date(final - start);
    alert(days);
});

<label for="from">From</label>
<input type="text" id="from" name="from" />
<label for="to">to</label>
<input type="text" id="to" name="to" />

This is what I have by far, I pretend to get the number of days passed between 2 dates everytime that final date is filled. I'm having some trouble because of conversions :s

Fiddle

$(function () {
    $("#from").datepicker({
        defaultDate: "+1w",
        changeMonth: true,
        numberOfMonths: 3,
        onClose: function (selectedDate) {
            $("#to").datepicker("option", "minDate", selectedDate);
        }
    });
    $("#to").datepicker({
        defaultDate: "+1w",
        changeMonth: true,
        numberOfMonths: 3,
        onClose: function (selectedDate) {
            $("#from").datepicker("option", "maxDate", selectedDate);
        }
    });
});

$("#to").change(function () {
    var final = $("#to").datepicker("getDate");
    var start = $("#from").datepicker("getDate");
    var days = new Date(final - start);
    alert(days);
});

<label for="from">From</label>
<input type="text" id="from" name="from" />
<label for="to">to</label>
<input type="text" id="to" name="to" />

This is what I have by far, I pretend to get the number of days passed between 2 dates everytime that final date is filled. I'm having some trouble because of conversions :s

Fiddle

• javascript
• jquery
• jquery-ui
• date
• datepicker

2 Answers 2

I believe THe biggest thing is that datepicker('getDate') returns a Date object already, so final and start are already date objects.

Now that you have two date objects you could the code samples in the following thread to get the number of days between them

How to calculate the number of days between two dates using JavaScript?

The following code is ripped right from the thread and google: you can fill in appropriately

var oneDay = 24*60*60*1000; // hours*minutes*seconds*milliseconds
var firstDate = new Date(2008,01,12);
var secondDate = new Date(2008,01,22);

var diffDays = Math.abs((firstDate.getTime() - secondDate.getTime())/(oneDay));

The following example worked fine for me.

$(document).ready(function(){
   var $datepicker1 =  $( "#firstday" );
   var $datepicker2 =  $( "#lastday" );
   $datepicker1.datepicker();
   $datepicker2.datepicker({
       onClose: function() {
           var fromDate = $datepicker1.datepicker('getDate');
           var toDate = $datepicker2.datepicker('getDate');
           // date difference in millisec
           var diff = new Date(toDate - fromDate);
           // date difference in days
           var days = diff/1000/60/60/24;

           alert(days);
       }
   });
});

Refer:- calculate number of days between two dates in jquery datepicker