working code example of jquery datepicker working as weekpicker

weekchooser.js.coffee

	weekchooser = -> 
		$('#datepicker').datepicker({
			dateFormat: "M d, yy",
			altFormat:	"M d, yy",
			altField:		"#actualdate",
			selectWeek: true,
			firstDay:		1,
			showOtherMonths: true,
			selectOtherMonths: true,
			beforeShow: -> 
				$('#datepicker').val($('#actualdate').val())
			onClose: (date) ->
				reformatWeek(date)
				this.blur()
		}).click -> 
			currentDay = $('.ui-datepicker-current-day')
			currentDay.siblings().find('a').addClass('ui-state-active')

		calendarTR = $('.ui-datepicker .ui-datepicker-calendar tr');
		calendarTR.live 'mousemove', (event) ->
			$(this).find('td a').addClass('ui-state-hover');

		calendarTR.live 'mouseleave', (event) ->
			$(this).find('td a').removeClass('ui-state-hover');

		reformatWeek = (dateText) ->
			$('#datepicker').datepicker('refresh')
			current = parseInt($('.ui-datepicker-current-day').find('a').html())
			weekstart = parseInt($('.ui-datepicker-current-day').siblings().find('a').first().html())
			weekend 	= parseInt($('.ui-datepicker-current-day').siblings().find('a').last().html())
			pattern = ///
				^([a-zA-Z]+)\s+([0-9]{1,2})(,.*)
			///
			[month, day, year] = dateText.match(pattern)[1..3]
			date = if weekstart > current
				first_month = relativeMonth(month, -1)
				"#{first_month} #{weekstart} - #{month} #{weekend}#{year}"
			else if weekend < current
				last_month = relativeMonth(month, 1)
				"#{month} #{weekstart} - #{last_month} #{weekend}#{year}"
			else
				"#{month} #{weekstart} - #{weekend}#{year}"
			$('#datepicker').val( date )

		relativeMonth = (month, c) -> 
			monthArray = $('#datepicker').datepicker('option', "monthNamesShort")
			index = monthArray.indexOf(month)
			if c > 0
				return if index + c > monthArray.length - 1 then monthArray[0] else monthArray[index + c]
			else
				return if index + c < 0 then monthArray[monthArray.length - 1] else monthArray[index + c]

	weekchooser()