day1='2014-03-31 00:00:01';

function get_day(day1,day2){
	var s = day1;
    var dt = Date.parse(s.replace(/-/g,"/"));
    var day1 = new Date(dt);
	
	var s = day2;
    var dt = Date.parse(s.replace(/-/g,"/"));
    var day2 = new Date(dt);
	
	var date3=day1.getTime()-day2.getTime()  //时间差的毫秒数
	//计算出相差天数
	return Math.floor(date3/(24*3600*1000))
}