Modifying the jQuery UI Calendar Date Selection

While working on an application I had a need to modify the way dates where selected from the jQuery UI calendar control.  I needed to only allow the end user the capability of selecting a Monday.  After some searching of the internet I found the following solution.

/* date picker week */
$(".dateweek").datepicker({
    showOn: 'both',
    buttonImage: '/Content/Images/ui/calendar.png',
    buttonImageOnly: true,
    firstDay: 1,
    beforeShowDay: function (date) { return [date.getDay() == 1, ""] }
});

I can’t remember where exactly I got it although I did make some modifications to it.  The code I actually used is above.