Ranked in these QuestionsQuestion Ranking
Pro GNOME Native integration
It has online accounts integration.
Pro Currently in active development
GNOME Calendar is improved with every release cycle of GNOME.
Calendar for GNOME aims to find the perfect balance between features and usability.
Con No support yet for WebCal
No support yet for WebCal, such as those offered by Facebook events.
A workaround exists. Since this application uses the same background services as Evolution, installing it and adding the WebCal calendars there, also adds them to GNOME Calendar.