Mexico DST news

Robert Elz kre at munnari.OZ.AU
Tue Jan 23 06:46:29 UTC 2007

    Date:        Mon, 22 Jan 2007 23:30:29 -0600
    From:        Jesper Norgaard Welen <jnorgard at>

  | I will elaborate it respecting changes on decree dates, but respecting
  | existing changes between decree dates, especially in the gap between 1948
  | and 1981.  [...]

I know this might seem a little obvious, but when you find something
like you have - a govt site that is setting out what looks to be
authoritative data, but which might not be perfect, the best thing to
do is probably to find the person who actually created the data, and
ask them where it came from.

That certainly won't be a politician (or is extremely unlikely to be),
but some bureaucrat, or perhaps external researcher.   Usually once you
find the right person (either an individual, or the real worker for a
committee) they'll tell you where their data comes from, and from that,
you'll have a much better idea how much trust should be placed upon that data.

That you're a member of the international group that documents all things
related to timezones will probably help you to actually make contact
with the appropriate person, the right approach is likely to be that you're
seeking more technical information than is given on the web page.

With this, it is important to be aware that the purpose of government
documents is almost never to illuminate history (or even to rewrite it,
however tempting it is sometimes to assign that as a motive).  Their
purpose is to keep the people happy with current events and future
changes - and since people mostly resist any change, one of the best
ways to overcome that is to shoe that the "change" is just something
that has happened repeatedly, and so is not a change, but just a regular
event...   To do that, publishing a history of what has happened in the
past can be very useful - but there's no need for such a history to be
extremely accurate.   If you want to convince people that moving the
dates for DST around is not such an unusual event, because it also
happened in 1917, and 1943, and ...  then you want to explain what
happened back then.  But to do that they don't need absolute accuracy,
which actual day in 1917 a change happened doesn't really matter to
anyone, nor for that matter whether it was really 1917 or 1918 or ...

They don't need that degree of accuracy, and while they aren't often
deliberately false in the statements made, they also have no particular
reason do do extensive historical research in order to be precisely
correct - if a report can be found that says something happened, that's
likely to be good enough, checking the accuracy of the report not really
needed (and for their purpose, that's even true).

What's more, since nothing nefarious is really happening, and no-one is
attempting to lay blame, there's no reason they wouldn't admit that some
of the details might be slightly inaccurate if you ask the right person.
You do have to find the right person though, others will tell you it must
be right because it is written in a govt document, they don't know it is
wrong (or where the data originates), so it must be right...


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