[tz] Irish Standard Time vs Irish Summer Time

Robert Elz kre at munnari.OZ.AU
Fri Jan 19 17:03:16 UTC 2018

  | From: Random832 <random832 at fastmail.com>
  | Date: Fri, 19 Jan 2018 11:12:28 -0500
  | Subject: Re: [tz] Irish Standard Time vs Irish Summer Time

  | It's also based on the plain english meaning of the term "DST"
  | and the words to which the abbreviation expands.

Since the plain English meaning of those words is nonsense in any case,
that hardly matters.

  | Daylight is not being "saved" by turning the clock back.

Daylight isn't being saved in any case, the period of daylight is just
being moved with respect to what the clock shows.  The amount of daylight
available is exactly the same.  This would be kind of like moving a dollar
from your right pocket to the left, and counting that as "saved".  What
was supposed to be saved (and which has I believe proved to be largely
ineffective) was power, not daylight, and given the right circumstances,
if that were to be possible, any clock adjustment might turn out to be
the right one.

  | If it were called tm_isalt (to match the "altzone" global from System V,

It was invented (the name) long before System V (or System anything)
was even a dream.  There was no "altzone" to reference, the abbreviations
were compiled in somewhere.

There's no question, when created, it was meant to indicate that (US)
summer time (daylight savings time) was in effect, and the 'D' rather
that 'S' forms of the tz abbreviations should be used.

  | but this name has a clear English meaning,

You're assuming that daylight savings time means that the clocks must
be put forward (which has been historically true, but there's no
logical, let alone "plain English" reason for that - it is just how
it has been).   Once again, avoid assuming that you know how clock
time works, you don't (nor do I, nor does anyone else).


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