In the resulting password entry pop-up, paste the app-specific password you copied onto the clipboard in the last section.
In the resulting Choose a Calendar window, select the calendar you want to set up4.
Back in the New Calendar window, choose a colour to match the one you use on iCloud.
Set your options: I select Copy calendar contents locally for offline operation, as I want to be able to access the calendar even if I don’t have an Internet connection, and Server handles meeting invitations.5
If you want this to be your default calendar, also check Mark as default calendar.
Set the Refresh every setting6 to decide how frequently your calendars should synchronise.
Press the OK button to create the calendar when you’re happy with your choices.
That’s it! If all goes well, you should see your calendar entries begin to pop up in Evolution. If you want to set up additional calendars, rinse and repeat the instructions in this section. Once you’ve set up your accounts, fire up Gnome Calendar and enjoy your synchronised calendars in a beautifully minimal interface. Any entries you make in Gnome Calendar will sync to iCloud and, from there, to all of your Apple toys, and vice-versa.