Nice question.and it's rather easy to arrive at the correct answer.

However, people should be beware of sys.time_zone_info because Microsoft have screwed up the time zones (both in sys.time_zone_info and in the registry: KEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones). They've omitted West European Time and invented an imaginary zone West European Standard Time which is identical to Central European Time. I image this is because someone misinterpreted the acronym WEST (S for Summer, not S for standard) which refers to WET+1 used in summer in the WET zone areas other than Iceland (ie it is the time used in summer in the parts of the WET zone that have "daylight saving time") and nobody at Microsoft bothered to check this (which could have been done very easily by looking at the page referenced in the first answer option, or by looking in wikipedia or at any decent encyclopedia). I can imagine chaos resulting from people looking for West European Time in the MS data, finding West European Standard Time, assuming that's what they want, and assigning the wrong offset for Dublin, Lisbon, London, Las Palmas, Reykjavík, Tórshavn and so on, thus being an hour out (MS's W European Standard Time is currently UTC+2, while everywhere in the West European zone is currently at UTC+1, except Iceland which doesn't use summer time and is currently UTC+0).