Description of problem: in gnome default apps the gnome-calendar is not selectable as default app in category calendar Version-Release number of selected component (if applicable): 3.32.1
Duplicate of bug 1712580 from Fedora 29. I also see this in F31 beta with gnome-calendar-3.34.1-1.fc31.x86_64.
*** Bug 1712580 has been marked as a duplicate of this bug. ***
This is because it's not capable of opening any calendar files. Needs to learn how to open files if it's to be selectable as a default app for opening files. Previously its desktop file lied about being able to open calendar files, allowing it to show up as a default app. But that was only ever a lie, and it made it difficult to open calendar files in apps that really could handle them, like Evolution.