问在时区设置javascript Fullcalendar插件(GMT + 8)

EN

<?php
    $datetime = new DateTime('now', 'America/Chicago');
    $datetime_string = $datetime->format('c');
?>

$('#calendar').fullCalendar({
    now: <?php echo json_encode($datetime_string) ?>
});

var currentTimezone = "Asia/Bangkok";
$('#calendar').fullCalendar({
                header: {
                    left: 'prev,next today',
                    center: 'title',
                    right: 'month,agendaWeek,agendaDay'
                },
                timezone: currentTimezone, << SET TIMEZONE HERE
                editable: true,
                selectable: true,
                eventLimit: true, // allow "more" link when too many events
            });