datepicker calculations

Question

I have the following code to ensure that if the user selects the same check in date as check out date for the conference, then the "total_days" = 1 if the difference in dates is > 0 - then it is supposed to update one more day for each one. ie "conference date in = 13.06.12" "conference date out = 13.06.12" - total days = 1 - this is correct. however, if "conference date in = 13.06.12", and "conference date out = 14.06.12", then "total_days" needs to be 2, instead of 1. what am I doing wrong? I have tried the following:

<td>Conference Date In</td>
    <td><input type="text" name="conference_date_in" id="conference_date_in" class="datepicker" /></td>
    <td>&nbsp;</td>
    <td>Conference Date Out</td>
    <td><input type="text" name="conference_date_out" id="conference_date_out" class="datepicker" /></td>
  </tr>
<td>Total Days</td>
    <td><input type="text" name="total_days" id="total_days" /></td>
  </tr>

<script type="text/javascript">

$(function() {
    $(".datepicker").datepicker({ minDate: -0, maxDate: "+100M +10D",dateFormat: 'dd-mm-yy'})
    ({
        changeMonth: true,
        changeYear: true,
    });
        });


var enquiry_date = $.datepicker.formatDate('dd-mm-yy', new Date());
document.getElementById('enquiry_date').value = enquiry_date;

var calcDate = function() {
    var start = $('#conference_date_in').datepicker('getDate');
    var end = $('#conference_date_out').datepicker('getDate');
    var days = (end - start) / 1000 / 60 / 60 / 24;

    if(days==0) {days=1
    }
    if( days >= 0 ) {
    document.getElementById('total_days').value = days;
    } 
        }


$('#conference_date_out').change(calcDate);
$('#conference_date_in').change(calcDate);

Answer 1

Posting this ass answer to close the issue.

Can't you just add 1 to the result of (end - start) / 1000 / 60 / 60 / 24;? You have to if's not if..else so this should resolve your issue.