I am a newbie also, but a couple off things come too mind. First- check with someone else at work who I
Has also linked calendars to see if that person experienced the same thing. It could be that recurring events are recorded from years ago and for years into the future. You should be able to pick & choose between the types of feeds... E.g. Holidays, meetings, weather, paydays.....
Also check your own events that repeat and feeds that you have. You might want to set an end date on repeating events and unsubscribe to some feeds.