What do you want to achieve? If you want to compare dates, you have already done the required bit.
var sDate = new Date(date1[0]+"/"+date1[1]+"/"+date1[2]);
var eDate = new Date(date2[0]+"/"+date2[1]+"/"+date2[2]);
if(sDate>eDate)
alert('start date is greater than end date');
else
if(eDate>sDate)
alert('end date is greater than start date');
else
alert('both dates are equal');