Google Calendar has a new permissions system in the works for Android
Separate from Android's own calendar permission
Android itself has a centralized permission that lets you allow or deny access to your calendars by third-party apps. This taps into the Calendar Provider API, which is like a bucket where all your upcoming events get dumped, and apps that have access to it can add, update, and delete these events. Now, it's starting to look like Google Calendar may move away from this system to one of its own design.
