When comparing BusyCal vs Calendar, the Slant community recommends BusyCal for most people. In the question“What are the best calendar apps for Mac OS X?” BusyCal is ranked 1st while Calendar is ranked 2nd. The most important reason people chose BusyCal is:
Alarms may displayed in the BusyCal Alarm Window or the Notification Center. Snooze alarms for any duration, including x minutes before start, Set default alarm intervals for new Events, To Dos, All-Day Events, and Birthdays & Anniversaries.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Custom Alarms and Snoozes
Alarms may displayed in the BusyCal Alarm Window or the Notification Center. Snooze alarms for any duration, including x minutes before start, Set default alarm intervals for new Events, To Dos, All-Day Events, and Birthdays & Anniversaries.
Pro Latteral bar
Pro Weather, moon-phases and graphics
Display a live 10-day weather forecast and moon phases. Drag-n-drop images into your calendar with the Graphics palette. Customize event fonts, sizes, styles and colors.
Pro Custom number of days/weeks
You can customize the number of weeks shown per month, or days shown per week
Pro Great support and development team
Pro Smart Filters
Create Smart Filters to display Calendar Sets, a custom view, or events that match a certain criteria with a single click.
Pro Integrated To Dos
To Dos can be displayed directly in your calendar and carry-forward until completed. To Dos in BusyCal are compatible and sync with the Reminders app on OS X and iOS.
Pro Snappy and light on resources.
Pro Sync with OwnCloud and others
Connections are more stable than in Calendar.
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.
Cons
Con Expensive
Con No MS Teams Meeting Integration
Con Displays parallel tasks strictly without overlap
This can lead to not being able to read text in Week view.
Con OSX and iOS Only
Keeps you tied into the Apple ecosystem, not that it's a con, just an observation.
Con Doesn't have a widget
Doesn't contain a widget for the Today section in the Mac Notification section.
Con Doesn't support sync of event colors from a Google calendar
Con Online sync only
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.