When I started writing a demo app for symptoms management, I thought it'd be cool to add the reminders directly into Android users' calendars instead of managing the notifications and clocks manually. I found out that Android Calendars can also be useful if one wants to manage events without actually creating and managing a database of events within an app.
Apart from reading Android Developer's documentation here, I also referred to a blog here that puts together all the information to get you started and running. However, bits and pieces of information are always missing and I decided to put together an example for people to start with.
You can find the example on Github here. Happy coding!