A(nother) daterange jQuery UI plugin (WIP)

jquery-ui-daterange.js

    $.fn.daterange = function( options ) {
        $( this ).each( function() {
            var element = $( this ),
                settings = $.extend( {}, $.fn.daterange.defaultOptions, options ),

                startDateField = $( settings.startDateField ),
                endDateField = $( settings.endDateField ),

                startDate = settings.startDate || null,
                endDate = settings.starDate || null;

            element.datepicker( $.extend( settings, {
                beforeShowDay: beforeShowDatepickerDay,
                onSelect: onDatepickerSelect,
            } ) );

            function beforeShowDatepickerDay( date ) {
                var className = '', showDay = true;

                if ( startDate !== null && endDate === null && date < startDate ) {
                    showDay = false;
                }

                if ( startDate !== null && endDate !== null && date >= startDate && date <= endDate ) {
                    className = 'ui-datepicker-selected-range';
                }

                return [ showDay, className, '' ];
            }

            function onDatepickerSelect( selected, datepicker ) {
                console.log( selected );
                if ( startDate !== null && endDate === null ) {
                    setRangeEndDate( element.datepicker( 'getDate' ), selected );
                } else {
                    resetRangeWithStartDate( element.datepicker( 'getDate' ), selected );
                }

                element.datepicker( 'refresh' );
            }

            function setRangeEndDate( date, formattedDate ) {
                endDateField.val( formattedDate );
                endDate = date;
            }

            function resetRangeWithStartDate( date, formattedDate ) {
                setRangeEndDate( null, '' );
                startDateField.val( formattedDate );
                startDate = date;
            }
        } );
    };

    $.fn.daterange.defaultOptions = {
        // daterange options
        startDate: null,
        endDate: null,
        startDateField: null,
        endDateField: null,
        // datepicker options
        numberOfMonths: 3,
    };