[Datetime-SIG] Computing .dst() as a timedelta

[M.-A. Lemburg]

On 20.09.2015 02:30, Tim Peters wrote:
> [Alex]
>> Tim, are you referring to the "Troll" rule? [1]  That's a strange beast
>> indeed and a comment above it says:
>>
>> # The CET-switching Troll rules require zic from tzcode 2014b or later, so
>> as
>> # suggested by Bengt-Inge Larsson comment them out for now, and approximate
>> # with only UTC and CEST. Uncomment them when 2014b is more prevalent.
> 
> Yes, and this was pointed out some time ago.  These really are the
> rules they use:
> 
>     http://www.timeanddate.com/time/zone/antarctica/troll

Interesting. It lists two "DST"s per year: they first
go from GMT to CET, then to CEST, and then back to CET and GMT.
I guess they switched to CET when the station was used and
to GMT for the instruments during winter when it was not used.

But this is not consistent with what the Norwegians report on their
Troll station website:

http://www.npolar.no/en/about-us/stations-vessels/troll/index.html

"""
The time zone Troll is located in, UTC +0, is 1 hour behind Norwegian
time (2 hours during summer time in Norway). Photo: Norwegian Polar
Institute
"""

The webcam confirms this: ftp://ftp.npolar.no/Out/TrollWebCam/TrollPublic.jpg

-- 
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