I live in a part of the world which has mistakenly decided to remain on DST permanently. A user noted this morning that our primary scheduling platform had experienced a similar failure to Google whereby updating the given timezones caused all the scheduled activities to just forward an hour.

Unfortunately, not having Google's bottomless pockets, the vendor was unable to apply a wholesale fix, although they are assisting with our manual adjustments.

I was informed by several users that "our old software didn't have this problem". They were highly dismayed to discover that yes, our old software had exactly the same problem with changes to timezone applicability, and; packrat that I am; that I could provide them with time stamped proof from the last time my local government decided to play fast & loose with DST.

We finished their specific corrections about an hour ago. The team is taking bets on whether they at least bother to say "Thank you".