Hello augustoMoreira,
You could try to use this approach to check is this date is recurrence or not.
$('#scheduler').on('appointmentClick', function (event) {
var args = event.args;
var appointment = args.appointment;
var isRecurrenceDate = !!appointment.recurrencePattern;
console.log(isRecurrenceDate);
});
Also I would like to suggest you to look at this topic:
http://www.jqwidgets.com/community/topic/editing-one-occurrence-of-repeated-appointment/
Best Regards,
Hristo Hristov
jQWidgets team
http://www.jqwidgets.com