Javascript function undefined

// How many days between two dates
function gDaysBetweenDates(date1, date2) {

    var date1_ms = date1.getTime();
    var date2_ms = date2.getTime();


    return Math.round(Math.abs(date1_ms - date2_ms) / (1000 * 60 * 60 * 24));

}

Date1 and date2 being passed are Date objects with 开发者_开发百科values like:

Tue Mar 09 2010 00:00:00 GMT+0000 (GMT Standard Time)

I get a problem when trying to extract the time, it says getTime is undefined. When I try and create a new date object with the dates passed in via:

var dateNew = new Date(date1);

I get the error, date is in invalid format.

For the last problem, run date1.constructor to see what kind of object date1 is. If it is a number is should work as you've written it. If it is a string, you have to make sure that it is formatted as a date. If it's anything but number or string you have an invalid type.

Also, make sure to check that date1 isn't null.

You seem to have some type problems. The Date constructor only accepts millisecond Numbers or date strings, not a date object. The other error sounds like you think something is a Date object which is in fact not. (null? a string?)