Last 12 months in Javascript

Question

I got an Kendo ui Chart like this one and have to show the last 12 months of todays date on the axis.
I found this to extend the date object to get the previous month. The problem seems to be when I got an Date like "2013/05/31" and the previous months got no 31st day.

Date.prototype.toPrevMonth = function (num) {
    var thisMonth = this.getMonth();
    this.setMonth(thisMonth-1);
    if(this.getMonth() != thisMonth-1 && (this.getMonth() != 11 || (thisMonth == 11 &&      this.getDate() == 1)))
    this.setDate(0);
}


new Date().toPrevMonth(11),
new Date().toPrevMonth(10),
new Date().toPrevMonth(9),
new Date().toPrevMonth(8),
new Date().toPrevMonth(7),
new Date().toPrevMonth(6),
new Date().toPrevMonth(5),
new Date().toPrevMonth(4),
new Date().toPrevMonth(3),
new Date().toPrevMonth(2),
new Date().toPrevMonth(1),
new Date().toPrevMonth(0)

Can anyone help me out with the if state?
The function is build to show only the previous month, but I need the last 12 previous months.

Or is there a much easier solution? :-)

Thanks for all!

Answer 1

Including year of month

var monthName = new Array("January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December");
var d = new Date();
d.setDate(1);
for (i=0; i<=11; i++) {
    console.log(monthName[d.getMonth()] + ' ' + d.getFullYear());
    d.setMonth(d.getMonth() - 1);
}

Answer 2

I also needed a list of the last 12 months this is what I did:

var theMonths = new Array("January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December");
var today = new Date();
var aMonth = today.getMonth();
var i;
for (i=0; i<12; i++) {
    document.writeln(theMonths[aMonth] + '<br>'); //here you can do whatever you want...
    aMonth++;
    if (aMonth > 11) {
        aMonth = 0;
    }
}