jquery datepicker, dates range count

Question

Hello,

i am trying to sum up or deduct dates in selected range using jquery datepicker, here is how i am doing it right now but without any luck.

function test(){
    var sundayCheck = 0;
    var saturdayCheck = 0;
    var totalDays = 0;

    sundayCheck = new Date($("#onlySunday").datepicker("getDate"));
    saturdayCheck = new Date($("#onlySaturday").datepicker("getDate"));

    totalDays = saturdayCheck.getDate() - sundayCheck.getDate();

    alert(totalDays);
}

thats a piece of code that should make calculation but what it does is just deducts days like,

24.01.10 - 06.02.10 = -18 which is totaly wrong as it should be more days its just does not consider the days and its just using first numbers of dates.

If anyone could help how to make such calculations i would appreciate the most.

Answer 1

Are you trying to dtermine the number of days between two dates?

  totalDays = Math.ceil((saturdayCheck.getTime()-sundayCheck.getTime())/(1000*60*60*24);

First get the number of milliseconds between the two dates then divide by the number of milliseconds in a day. Using Math.ceil to round up to nearest integer.

Answer 2

DAY_MSECONDS = 1000 * 60 * 60 * 24; // m-seconds in a day
var d1_ms = sundayCheck.getTime(); // date1 
var d2_ms = saturdayCheck.getTime(); // date2
var days = Math.ceil(Math.abs(d1_ms - d2_ms) / DAY_MSECONDS);

The reason you are getting -18 is because of the way javascript deals with subtracting strings. First they are evaluated to integers with whatever the default radix is, in most cases 10. So what you are doing is effectively

totalDatys = parseInt(saturdayCheck.getDate(), 10) - parseInt(sundayCheck.getDate(), 10);

which results in

totalDatys = 6 - 24