code: function(picker, calendar, inst) {
  			var target = $(this);
  			picker.find('th span').each(function() {
  				if (this.parentNode.className.match(/.*calendars-week.*/)) {
  					return;
  				}
  				$('<a href="javascript:void(0)" class="' + this.className +
  						'" title="Change first day of the week">' + $(this).text() + '</a>').
  					click(function() {
  						var dow = parseInt(this.className.replace(/^.*calendars-dow-(\d+).*$/, '$1'), 10);
  						target.calendarsPicker('option', {firstDay: dow});
  					}).
  					replaceAll(this);
  			});
  		}
docs: Change the first day of the week by clicking on the day header.
  Found in the <code>jquery.calendars.picker.ext.js</code> module.
  @memberof CalendarsPicker
  @param picker {jQuery} The completed datepicker division.
  @param calendar {BaseCalendar} The calendar implementation.
  @param inst {object} The current instance settings.
  @example onShow: $.calendarsPicker.changeFirstDay