diff -u /tmp/good /tmp/bad
--- /tmp/good	2021-02-17 13:48:44.724024989 +0100
+++ /tmp/bad	2021-02-17 13:49:17.820001476 +0100
@@ -153,20 +153,25 @@
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+RRULE:FREQ=YEARLY;UNTIL=19940925T010000Z;BYDAY=-1SU;BYMONTH=9
 END:STANDARD
 BEGIN:DAYLIGHT
 TZNAME:CEST
 DTSTART:19810328T020000
 TZOFFSETFROM:+0100
 TZOFFSETTO:+0200
-RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3
+RRULE:FREQ=YEARLY;UNTIL=19950326T010000Z;BYDAY=-1SU;BYMONTH=3
+END:DAYLIGHT
+BEGIN:DAYLIGHT
+TZNAME:CEST
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+TZOFFSETFROM:+0100
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 END:DAYLIGHT
 BEGIN:STANDARD
-TZNAME:CET
-DTSTART:19961031T030000
-TZOFFSETFROM:+0200
-TZOFFSETTO:+0100
-RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
+TZNAME:CEST
+DTSTART:19950924T030000
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
 END:STANDARD
 END:VTIMEZONE