日期leap年验证

Question

function checkDate(date)
{
        //how to use this function since many people recommend this one
    isLeap = new Date(date, 1, 29).getMonth() == 1;
    return isLeap;

}

In html script, i wrote it as but i can't validate my Date of Order. I need to use javascript and it should be able to validate it including leap year. The function I used above can't work. Any helps will be appreciated.

Answer 1

To check if it's leap year :

var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));

to check if the extra day is valid -- is to check how many days were in that month (and if they equal to dd):

32 - new Date(2000, 1, 32).getDate() //1 here is FEB

do if some says : 29 feb 2000

so 32 - new Date(2000, 1, 32).getDate() //29

which is fine . cuz 29==29.

BUT

do if some says : 29 feb 2001

32 - new Date(2001, 1, 32).getDate() //28

and 28!=29 so it's not valid date.