When comparing Calendar vs Morgen.so, the Slant community recommends Calendar for most people. In the question“What are the best calendar apps for Mac OS X?” Calendar is ranked 2nd while Morgen.so is ranked 5th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro GNOME native integration
Pro Currently in active development
GNOME Calendar is improved with every release cycle of GNOME.
Pro Simplicity
Calendar for GNOME aims to find the perfect balance between features and usability.
Pro Synchronisation
It has online accounts integration.
Pro Supports general CalDAV calendars
Pro Google synchronization
Connects to your Google accounts via OAuth.
Pro Easy to setup
Connecting to service accounts (such as Exchange) is easy and straightforward.
Pro Natural language
It supports interaction using natural language (English). For example "Schedule a meeting with John tomorrow at 11".
Pro One-click installation
First installation and updates are done with only 1 click.
Pro Supports Exchange calendars
Including Exchange, Outlook.com and Office 365 accounts.
Pro Free
Totally free and in active development.
Cons
Con Cannot print
Con Extremely buggy
Con Poor interoperability with online calendars
Does not connect to Fastmail.
Con Far too simple
Con FAR too tied into the GNOME infrastructure
The UI and configuration presume you are running GNOME, and has the ugliness of a GNOME application. Configuration, as is usual for any GNOME application, is pretty much nonesistent.
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 Can't import ics files
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 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 Only works on GNOME
