Re: [h-e-w] Cannot set start of daylight savings time

[Eli Zaretskii]

> Date: Thu, 14 Mar 2013 09:39:29 -0700 (PDT)
> From: bostjanv <address@hidden>
> 
> Emacs manual states that to change the start or end of daylight savings time
> from the default value (Cambridge, Massachusetts, USA), one has to change
> the values of calendar-daylight-savings-starts and
> calendar-daylight-savings-ends. However, all my attempts to do so are
> failing. I am using the call of emacs (version 24.2.1), "runemacs
> --no-splash --no-site-file", and the following simple init.el file:
> 
> START OF FILE
> (load "cal-dst")
> 
> (setq calendar-daylight-savings-starts '(calendar-nth-named-day -1 0 3
> year))
> ;(setq calendar-daylight-savings-starts nil)
> (setq calendar-daylight-savings-ends '(calendar-nth-named-day -1 0 10 year))
> ;(setq calendar-daylight-savings-ends nil)
> (setq calendar-daylight-time-offset 60)
> (setq calendar-daylight-savings-starts-time 180)
> (setq calendar-daylight-savings-ends-time 180)
> END OF FILE
> 
> after which I evaluated the form
> 
> (format-time-string "%H:%M ")
> 
> None of the two values seen above (one of which is commented out) result in
> any change (I always get the Cambridge, Massachusetts version). Can someone,
> please, tell me what I am doing wrong?

I don't see how this variable can affect format-time-string.  The doc
string of calendar-daylight-savings-starts says:

     Sexp giving the date on which daylight saving time starts.
  This is an expression in the variable `year' whose value gives the Gregorian
  date in the form (month day year) on which daylight saving time starts.  It is
  used to determine the starting date of daylight saving time for the holiday
  list and for correcting times of day in the solar and lunar calculations.

Note the last sentence: my interpretation of it is that the value
affects only calculations within the calendar package.  I see nothing
in the code to suggest otherwise: the only references to it are within
the calendar package.

The Emacs manual says:

     Emacs uses these expressions to determine the starting date of
  daylight saving time for the holiday list and for correcting times of
  day in the solar and lunar calculations.

which implies the same.  (And this whole description is in a
sub-section of the "Calendar/Diary" section, not in some general
section regarding time display.)

So I think you simply expect of this variable something that it cannot
provide.