Just came acroos an Appointment Reminder Software named Apptoto, Set up Apptoto once and its off an running, automatically reminding your clients of their appointments and updating your calendar at the same time. No need for you to manually remind clients.
So, if you ever in need of such software that might be suitable for you.
Note: Please note that this is just for education purpose and I personally not belong to any activity of this software, nor having any refferel benefits.