jQuery UI Picking a start and end date within range based on start date

Question

I\'m building a date picker in jQuery ui. What I\'m trying to do is set a range, so when they pick the first date the second date appears and gives a 30 day window. I tried this

Answer 1

$("#start_date").datepicker().on('changeDate', function(selected){
        startDate = new Date(selected.date.valueOf());
        $('#end_date').datepicker('setStartDate', startDate);
    });  

    $("#end_date").datepicker().on('changeDate', function(selected){
        startDate = new Date(selected.date.valueOf());
        $('#start_date').datepicker('setEndDate', startDate);
    });