Your reminders can send via SMS or via email or both.
You can send as many reminders as you need to, for example one a week before and another 24hrs before an appointment.
Reminders are fully customisable so you can make them your own, go to settings > reminders.
Reminders can also be sent as 'miss you' reminders that make sure your clients never forget to rebook. There are also pet birthday reminders and deposit reminders too!