Ranked in these QuestionsQuestion Ranking
Pro GNOME Native integration
Pro Currently in active development
GNOME Calendar is improved with every release cycle of GNOME.
It has online accounts integration.
Calendar for GNOME aims to find the perfect balance between features and usability.
Con Extremely Buggy
Con Continues to pop-up reminders that are turned off and they cannot ever be removed
The GNOME Calendar displays pop-ups from an old Google Calendar that was used. That Google Calendar has long since been removed from GNOME, and even with the notifications turned off on the GNOME Calendar, the pop-ups still happen.
Con Can't read 'all-day' events with dark theme
Text is white on light blue with dark themes. The workaround: assign all-day events to just one hour.
Con Incorrect appointment times when importing .ics calendars
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.
Con Poor interoperability with online calendars
Does not connect to Fastmail.