Excellent support from Apple
Mark Ford
I was having trouble synchronising the Calendar entries on my Mac, iPad, iPod Touch & the Cloud - so much so that I couldn't rely on them at all. [All on the latest OSes]I hunted about on the net but got nowhere so I went to https://getsupport.apple.com, made the appropriate selections, filled in the form and they phoned me in about 4 minutes.
For the next couple of hours the patient, non-judgmental bloke at Apple took me through a host of possibilities [several took a while to sync as my internet link is not the fastest] and in the end he solved it.
Brilliant free service from Apple.