Everything Apple Calendar Left Out
I originally got BusyCal because Apple Calendar was having trouble syncing with all my different calendar servers. Since then Apple has fixed the Calendar bugs, but I stuck with BusyCal. It has a cleaner UI, and adds all the little features and configuration options that Calendar is missing. Plus, there is real support if you have a problem. In El Capitan some of the animations were disabled, which I hope gets re-added in the future. Worth it!
Drvickery22 about
BusyCal 2