To get rid of these problems with DST I changed the startUp of ICU
MSKICUApp>>startUp
| estzd |
MSKLocale clearCurrent.
"Patching the errors in 8.5.2 - does nothing on earlier releases"
"nicer way - thanks to Tom Koschate"
estzd := 'EsTimeZoneDatabase' abrAsClass.
estzd notNil ifTrue:[
estzd singleton notNil
ifTrue:[ estzd singleton
defaultLocation: UCalendar getDefaultTimeZone
]
]
Schrievkrom 
You can send #abrAsClass to a string to get nil or the real class. However, in practice, you’ll find that you need to include the TimeZones app in order to package (I’ve opened case INST50031 on this).
I appreciate the mention, but could I impose on you to spell my name correctly? :{)
Corrected.