Use php array to disable dates in datepicker and times in timepicker from onSelect in DatePicker

I have a datepicker input and a timepicker input that I'd like to use to schedule a person for appointments.

When the user clicks on the input to open the datepicker menu, I'd like to grey out specific datetimes. I've got a php function that returns this array of datetimes in in 'Y-m-d H:i:s' string format. But I dont' know how to use that function's return value to give the javascript function what it needs to disable a range of dates in datepicker.

In the onSelect event of my datepicker, I want it to enable/disable time options in my timepicker according to which timeslots are booked for that day. But I don't know how.

1. Datepicker uses beforeshowDay: to disable booked dates

2. user selects date from datepicker

3. Datepicker enables/disables times in the timepicker

I did find out how to disable timeranges in the timepicker Here. the code example is this:

$('input.timepicker').timepicker({
    'disableTimeRanges': [
        ['1am', '2am'],
        ['3am', '4:01am']
    ]
});

But that's how I'd disable the time ranges from within the scope of the timepicker. I don't know how to disable them from BeforeShowDay in datepicker?

<script type="text/javascript">   
    $(document).ready(function(){
        $( "#datepickerListAppointments" ).datepicker(
        {
            minDate:'0',
            beforeShowDay:
            function(dt)
            {   // need to disable days other than tuesday and wednesday too.
                return [dt.getDay() === 2 || dt.getDay() === 3, ""];
            },
            onSelect : function(){
                should disable/enable timepicker times from here?
            }
        });

        $('input.timepicker').timepicker({
            timeFormat: 'h:mm p',
            interval: 90,
            minTime: '9',
            maxTime: '10:30am',
            defaultTime: '9',
            startTime: '9:00',
            dynamic: false,
            dropdown: true,
            scrollbar: false                
        });

    });

This is the function that gives the datetimes, in case it helps to know.

function get_next_open_appointments($numAppointments, $timeSlotToExclude = "")
{
    global $db;
    $whereCondition = "WHERE FirstName = :null ";
    if ($timeSlotToExclude != "")
    {
        $whereCondition .= "AND AppointmentTime != '$timeSlotToExclude' ";
    }

    $query = "SELECT DISTINCT AppointmentTime FROM appointments
              $whereCondition
              ORDER BY AppointmentTime ASC LIMIT $numAppointments";
    $statement = $db->prepare($query);
    $statement->bindValue(':null', "");
    $statement->execute();
    $datesArray = array();
    while ($row = $statement->fetch()) 
    {
        array_push($datesArray, $row['AppointmentTime']);
    }
    $statement->closeCursor();
    return $datesArray;
}

UPDATE:

Hugo De Carmo pointed me in the right direction and I got the dates to disable/enable appropriately. However, I don't know how to use the datetimes that I pulled in code below to disable/enable times in the timepicker.

Here is the new code:

<script type="text/javascript">   
    $(document).ready(function(){

        // uses php to get open appointments, and put them in a javascript array
        <?php $datetime_openings = get_next_open_appointments(200);
        $date_openings = array();
        foreach ($datetime_openings as $dt)
        {
            array_push($date_openings, substr($dt,0,10)); // just the date part
        }

        $json_date_openings = json_encode($date_openings);
        echo "var arr_Openings = ". $json_date_openings . ";\n";
        ?>

        $( "#datepickerOpenAppointments" ).datepicker(
        {
            minDate:'0',
            beforeShowDay:
            function(dt)
            {
                var string = jQuery.datepicker.formatDate('yy-mm-dd', dt);
                var bFound = (arr_Openings.indexOf(string) != -1);
                return [ bFound ]; 
            },
            onSelect : function(){
               //    Should disable/enable time ranges here?
        });

        $('input.timepicker').timepicker({
            timeFormat: 'h:mm p',
            interval: 90,
            minTime: '9',
            maxTime: '10:30am',
            defaultTime: '9',
            startTime: '9:00',
            dynamic: false,
            dropdown: true,
            scrollbar: false                
        });

    });