String.convertToDate.js is a small extension method for the javascript String class. It's used to convert a string to a Date object by specifying a format string.

String.convertToDate.js

/*
The following code extends String class so that you can use convertToDate on a string object.
format can be a combination of "yy" or "yyyy" for year, "mm" for month and "dd" for day.
format is case-insensitive.
The seperator between date part markers may be "/", "." or "-".
Some examples:
"2016-12-31".convertToDate("yy-mm-dd") (same as "2016-12-31".convertToDate("yyyy-mm-dd"))
"31.12.2016".convertToDate("dd.MM.yyyy")
"12/31/2016".convertToDate("MM/dd/yyyy")
*/
String.prototype.convertToDate = function (format) {
	var formatParts = format.toLowerCase().split(/[/.-]/);
	var dateParts = this.split(/[/.-]/);
	var yearIndex, monthIndex, dayIndex;
	for(var i=0; i < formatParts.length; i++) {
		if(formatParts[i] === "dd") dayIndex = i;
		if(formatParts[i] === "mm") monthIndex = i;
		if(formatParts[i] === "yy" || formatParts[i] === "yyyy") yearIndex = i;
	}
	return new Date(Number(dateParts[yearIndex]), Number(dateParts[monthIndex]) - 1, Number(dateParts[dayIndex]))
}