isDST for timezones with negative DST offset (like Europe/Dublin) is reverse of expectations (of e.g. CLDR)

[arjanmels]

The isDST flag is false during summer and true during summer in Europe/Dublin. This is because a negative DST is used in the default versions of tzdb (since ~2018). (background info: Time_in_the_Republic_of_Ireland.)

However this is reverse with expectations from CLDR and therefore incorrect timezone names are retrieved (https://cldr.unicode.org/development/updating-codes/update-time-zone-data-for-zoneparser).

It can be fixed by using the rearguard version of the tzdb, see Pull Request #205.