Question

I’m trying to convert a date in javascript from MM/dd/yyyy to yyyy/MM/dd

so this works:

var d = new Date("08/08/2012");
dateString = d.getFullYear() + "/" + d.getMonth() + "/" + d.getDate();
document.write(dateString);

output = 2012/7/8

///////////////////////////////////////////////////

this does not:

var dateString = "08/08/2012";
var d = new Date(dateString);
dateString = d.getFullYear() + "/" + d.getMonth() + "/" + d.getDate();
document.write(dateString);

and neither does this:

var dateString = "08/08/2012";
var d = Date.parse(dateString);
dateString = d.getFullYear() + "/" + d.getMonth() + "/" + d.getDate();
document.write(dateString);

how do I make it work with a string variable? thanks

~Myy

Answer 1

var dateString = "08/08/2012";
var d = new Date(dateString);
dateString = d.getFullYear() + "/" + d.getMonth() + "/" + d.getDate();
document.write(dateString);

That should, and does, work. Keep in mind that JavaScript stores months as a zero-indexed value.

If you want to have leading zeros, then you’ll have to do some magic:

var dateString = "08/08/2012";
var d = new Date(dateString);
dateString = d.getFullYear() + "/" + ('0' + (d.getMonth()+1)).slice(-2) + "/" + ('0' + d.getDate()).slice(-2);
document.write(dateString);​

jsFiddle

The reason why your Date.parse( ) example is not working, is because that function returns a timestamp (number of milliseconds since 1970), instead of a Date object. Therefore, you can’t call functions like getFullYear() on the timestamp.