There seems to be a synchronization issue on some Android devices. Any calendar app renders recurring events a couple hundred times. Pretty annoying, cause it gets slow as hell and my smartwatch constantly chokes on all the notifications. This little Python script transforms all recurring events within a two-year timespan to single event instances. Thus, it's hacky but it solves the issue.
Go through the tutorial at https://developers.google.com/calendar/quickstart/python.
As a last step call python transform.py
.
Done!