Issue in date foarmat in JQuery datepicker

Issue in date foarmat in JQuery datepicker

I have 2 datepicker which binds to textboxes Chkin and Chkout. I need to
display dates in dd/mm/y JQuery datepicker format. Problem is that when I
try to get getFullYear() method of a dd/mm/y formatted date, I get result
as of 19th hundred(as I know default starts with 1900). So when ever I
select a date in my first datepicker, second date picker year changes to
1913(August 1913 in month view of August in datepicker 2) what I expected
is 2013. Below is my code-
$("#Chkin").datepicker({
dateFormat: 'dd/mm/y',
minDate: '+0',
onClose: function (dateText, inst) {
if ($("#ctl00_ContentPlaceHolder1_hdnDateformat").val() ==
"dd/mm/y") {
var parts = dateText.split("/");
var cin = new Date(Number(parts[2]), Number(parts[1]) - 1,
Number(parts[0]));
} else {
var cin = new Date(dateText);
}
var chkout = new Date(cin.getFullYear(), cin.getMonth(),
cin.getDate() + 1);
var maxCOut = new Date(cin.getFullYear(), cin.getMonth(),
cin.getDate() + 7);
$("#Chkout").datepicker('option', 'minDate', chkout);
$("#Chkout").datepicker('option', 'maxDate', maxCOut);
$("#Chkout").datepicker("setDate", chkout);
}
});