Even google isn't quite sure about the summer time.
Not sure if that is just a Google German thing...
A few weeks ago I tried to find out what the current time in CET is.
Asking google for "CET" gave me: "23:27 CET".
Asking google for "CET time" (I know that "time" is twice in this case) gave me "00:27 CET".
The last one is wrong and should be CEST or even more correct would be just the same result for CET as I asked for
I am always forgetting the polarity. Seeing the cut-overs listed helps me:
$ zdump -v Europe/Berlin | grep 2021
Europe/Berlin Sun Mar 28 00:59:59 2021 UT = Sun Mar 28 01:59:59 2021 CET isdst=0 gmtoff=3600
Europe/Berlin Sun Mar 28 01:00:00 2021 UT = Sun Mar 28 03:00:00 2021 CEST isdst=1 gmtoff=7200
Europe/Berlin Sun Oct 31 00:59:59 2021 UT = Sun Oct 31 02:59:59 2021 CEST isdst=1 gmtoff=7200
Europe/Berlin Sun Oct 31 01:00:00 2021 UT = Sun Oct 31 02:00:00 2021 CET isdst=0 gmtoff=3600
In this case, Google is providing a wrong answer to not confuse people. People don't understand that a time zone can exist but not be observed at the same time
I make a point to give local times in just "PT". Not least among my reasons is that I can't ever remember which half of the year is Daylight time and which is Standard.
It's especially annoying when dealing with multiple countries that may or may not be using Daylight Saving Time.