So I've gone through this article and tried the steps that I could. One of the problems with this article is that it does not address OS X Yosemite (10.10) nor iOS 8.1. There is something that keeps changing repeating events back to their original form after I have edited them and said to only change that event and not the future events. (I use this method for monthly bills which have different amounts, slightly different due dates and I put in the notes when I paid or mailed them. When they change back, all that info is gone!) I've tried to edit the repeating event in iCloud and it will update on my MacBook Air but then if I open Calendar on my iPhone, the event will get changed back to its unedited state. However, I don't think this is a consistent pattern. Something, I'm not sure what, can change the edited event back, at some point in time, from somewhere. I also found where the repeating event is edited on my MacBook Air but unedited in iCloud with no sign of the edited event. I have not been able to find a pattern.
I also get two copies of the same alert. If I click on the alert, it will show me the event in Calendar; if I click on the second alert for the same event, it shows me nothing--like it does not really have the event there.
I think it has to do with the calendar called "Calendar" which I did not create & don't use; it showed up after I migrated from my old MacBook. If I try to uncheck that calendar, ALL my calendars vanish from Calendar on my MacBook Air! (Very disconcerting!)
My workaround is to edit the repeating event as I need to, copy it, paste it and then delete the "repeating" event only (not all future events). However, I can cut & paste in Calendar on the MacBook Air only; I can't do that to events on the iPhone.
I can't trust Calendar to help me keep track of stuff. I'm afraid to use it on my iPhone because I don't know if that makes the edited events go back to their unedited state or if changes I make will make it to my MacBook Air. . Very .