Sistema de agendamento com datepicker

    <label class="label">
        <span>Selecione um dia:</span>
        <select name="appointment_schedule_id" class="horarios">
            <option selected disabled value="">Nenhum Selecionado</option>
            <?php
            $read->readFull("SELECT 

                                *
            
                                FROM schedule s 
                                WHERE s.schedule_status IS NULL 
                                    AND s.schedule_tstamp >= CURRENT_TIMESTAMP 
                                GROUP BY s.hora_disp
                                ORDER BY s.schedule_tstamp ASC");
                                

            $schedules = ($read->getResult() ? $read->getResult() : null);

            if (!empty($schedules)) {
                foreach ($schedules as $schedule) {
                    $schedule = (object) $schedule;
                    echo "<option value='{$schedule->schedule_id}'>" . date('d/m/Y', strtotime($schedule->schedule_tstamp)) . "</option>";
                }
            }
            ?>
        </select>
    </label>

    <div>
        <select class="hora" style="display: none;">
        
        </select>
    </div>

    <p>
        <button type="submit" class="btn">Marcar Agendamento!</button>
    </p>
</form>

<script>
    $(".horarios").on("change", function() {
        var idHora = $(".horarios").val();

        $.ajax({
            url: 'busca_hora.php',
            type: 'POST',
            data:{id:idHora},
            beforeSend: function()
            {
                $(".hora").css({'display': 'block'});
                $(".hora").html("Carregando...");
            },
            success: function(data) 
            {
                $(".hora").css({'display': 'block'});
                $(".hora").html(data);
            },
            error: function(data) 
            {
                $(".hora").css({'display': 'block'});
                $(".hora").html("Houve um erro");
            }
        });
    });
</script>

<?php

require_once 'conexao.php';
 
$pega_hora = $conexao->prepare("SELECT 
									
									*

									FROM horas_disp
									WHERE schedule_id='".$_POST['id']."'
									/*AND s.schedule_time >= CURRENT_TIMESTAMP */
									");


$pega_hora->execute();

	$fetchALL = $pega_hora->fetchALL();

		foreach ($fetchALL as $horas_disp) {
			echo '<option>'.$horas_disp['horario_disp'].'</option>';
		}