爱在西元前

/**
* 2011-07-19 gongwy
* javascript 日期加减
* DateNextDay,returnMonth
* alert(DateNextDay("2011-07-31",2));
*
*/
function DateNextDay(d2,num) {
// slice返回一个数组
var str = d2.slice(5) + "- " + d2.slice(0, 4);
var d = new Date(str);
var d3 = new Date(d.getFullYear(), d.getMonth(), d.getDate() + num);
var month = returnMonth(d3.getMonth());
var day = d3.getDate();
day = day < 10 ? "0" + day : day;
var str2 = d3.getFullYear() + "-" + month + "-" + day;
return str2;
}

// 返回月份
function returnMonth(num) {
var str = " ";
switch (num) {
case 0 :
str = "01";
break;
case 1 :
str = "02";
break;
case 2 :
str = "03";
break;
case 3 :
str = "04";
break;
case 4 :
str = "05";
break;
case 5 :
str = "06";
break;
case 6 :
str = "07";
break;
case 7 :
str = "08";
break;
case 8 :
str = "09";
break;
case 9 :
str = "10";
break;
case 10 :
str = "11";
break;
case 11 :
str = "12";
break;
}
return str;
}