Dear Yves,
when I create recurring appointments wednesday(until 2017-12-31) with a start at 13:00 and a end at 14:00 without display the registration deadline, the meetings are at correct time until 21th of october. from the 28th it is one hour earlier. I think there is a BUG with timechange.
If you need more informations, please write me back.
Regards, Christian