Do you rely on Google Calendar for everything? Google Calendar is one of those most used programs because it is user friendly and integrates with most progrrams and apps. Sometimes it can be so time consuming to send out appointment reminders and sometimes you just forget.
I have just found the best program to automate my system, Zapier. With Zapier you can set up a zap for your Google Appointments to be sent automatic reminders, choose from minutes before, hours, days, weeks and let Zapier do the work for you.
With the free version you are allowed 5 free zaps and up to 100 tasks per month. Tasks are defined as every time a zap occurs.
So if you are not wanting to spend money on an extra subscription then why not use Google Calendar and Zapier together and streamline your process.