When comparing Fantastical 2 vs Calendar, 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 Fantastical 2 is ranked 3rd.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Very polished natural language text entry
Fantastical makes it really easy to add events using their superb natural language parser. For instance, an entry like "breakfast at 9am at The Diner" will be handled correctly.
In addition to their best in class natural language processing, Fantastical has awesome features such as allowing users to append "/work" or "/personal" in order to add events to the specified calendar and setting up abbreviations that will add snippets of text.
Pro Awesome syncing support
Google, iCloud, Facebook, CalDAV, Exchanged, and iPhone calendar are all supported out of the box.
Pro "Dayticker" is a great way to quickly see appointments
Although pretty simple, the Dayticker view, located at the top of the user interface, is simply fantastic for quickly seeing which days are booked out. It also acts as a convenient way to add new events (long press on a day).
Pro Displays inline map of the event's location
The app displays inline map of the event's provided location. Additionally, users can choose between Apple's Maps or Google's Maps applications to use the feature with.
Pro Allows adding reminders
Using the natural language parser, reminders can be added with the keywords "reminder", "todo", "task", or "remind me to."

Pro Syncs with iOS reminders
Existing reminders can be used or adde with Siri.
Pro Functions as a widget
With Fantastical 2, the calendar can be accessed through a widget in order to save time.
Pro Gesture driven
Fantastical 2 lets users flick, scroll, and swipe to quickly move through different views and types of information.
Pro Custom colors
Tasks can be color coordinated in order to see their categories at a glance.
Pro Resizeable window
The divider between the two views can be dragged for customized viewing.
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 Uses “dots on a day” style interface
This is not the way calendars should work.
Con V2 discontinued, V3 too expensive as a subscription model
Con Only one way to display your events
It would really help to have an actual calendar with the events written into it instead of a list and dots.

Con Have to pay again for the iPad version
Con Not as good as Moleskine cal
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
