Not sure if this is an events planning bug or a Companion display bug - but events timing through the DST switch last weekend was wrong. Before DST switch, looking at events scheduled after the switch showed them offset by one hour (early). After the DST switch, events ended up in the right place, not sure if it was immediate or not. This looks like a discrepancy in DST treatment between whatever tool and DB are used to plan events, and Companion’s view into that DB.
Don’t feel bad, Microsoft still can’t do that correctly in Outlook either.