Add ymd prototype to Date object to format javascript dates as Y-m-d

gistfile1.js

// Prototype for js Date object to format in Y-m-d
Date.prototype.ymd = function() {
	var yyyy = this.getFullYear().toString();
	var mm = (this.getMonth()+1).toString();
	var dd = this.getDate().toString();

	return yyyy + '-' + (mm[1] ? mm : '0' + mm[0]) + '-' + (dd[1] ? dd : '0' + dd[0]);
}