California is a new, simple, calendar app for Fedora from the Yorba crew (developers of shotwell and the geary email app). You can try out california on Fedora 20 using this COPR repo.

California is simple and to the point. It shows your calendar, appointments, and lets you add appointments too. Pretty much all you need from a calendar app. It is also integrated with the “evolution data server” (the backend service that stores calendar data in Fedora), so your calendars appear in the drop-down when you click the clock at the top of the Fedora desktop.