计算两个日期之间的总周数和天数？

Question

这样它将显示1周6天

代码：

var d1 = tblLNMP.rows[0].cells[1].getElementsByTagName("span")[0].innerHTML;
var d2 = tblLNMP.rows[0].cells[3].getElementsByTagName("span")[0].innerHTML;
var date1 = new Date(d1);                                               
var date2 = new Date(d2);
var timeDiff = Math.abs(date2.getTime() - date1.getTime());                             
var diffDays = Math.ceil(timeDiff / (1000 * 3600 * 24));
var numberOfWeeksAndDays = diffDays / 7; // Will return decimal

示例：

date1 = 07/01/2014
date2 = 07/14/2014
Should display 1 Week and 6 Days but with my current code it returns 1.8xxxxx
Getting the number of weeks I suppose is easy but getting the number of days if not     divisible by 7 is a challenge for me.

请忍受javascript noob。