[R-sig-finance] RE: Rmetrics - timeDate Class
ggrothendieck at myway.com
Sun Jun 13 18:36:57 CEST 2004
I would like to clarify my suggestion.
My suggestion was simply how to implement the current functionality
without making the user set environment variables.
Whether time zones are important or not does not seem to be
relevant to that discussion since I was not proposing to change
any outward functionality -- just how to implement the existing
functionality in more convenient way.
Date: Sun, 13 Jun 2004 15:03:22 +0000
From: Diethelm Wuertz <wuertz at itp.phys.ethz.ch>
To: <ggrothendieck at myway.com>, <r-sig-finance at stat.math.ethz.ch>
Subject: Rmetrics - timeDate Class
Many thanks for your suggestion,
I don't know if your suggestion works. I had many problems in
properly and therefore I decided to do it the way I did it, in GMT +
information. Here comes an example:
In the eighties a trader in Frankfurt is awating the closing prices from
exchange. When gets he or she the information in local time? It's not
the same time
in Frankfurt as in Zurich although both cities belong to the same time
in the eighties Zurich and Frankfurt moved to DST at different dates
there is a
difference of one hour for some dates!
I know of some other critical examples, and so I decided to work
GMT excluding all time zone information. The problem is that Zurich and
cannot be distinguished by the time zone alone. One needs more
I use for both Zurich and Frankfurt GMT with the (different) DST info
the timezone database. Otherwise I have to introduce DST-MET (Middle
Time) in several ways for different cities in Europe.
Maybe there is a better solution to such problems ...
The whole timedDate class still needs much more testing ... (I did it to
under MS Windows)
I put this on the R-sig-finance discussion list, because I think these
are of more general interest.
>From: Diethelm Wuertz <wuertz at itp.phys.ethz.ch>
>>Suggestions are welcome!
>It would be nice if one did not have to set their time zone to GMT.
>One implementation might be to capture the time zone on entry to
>the relevant functions, set the time zone to GMT, run the function
>and restore the time zone on exit.
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