Re: TimeZones and politics Re: How to tell (in advance) if a date-time is ambiguous?

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On Wed, Jul 12, 2017 at 11:07 AM, Binarus <[email protected]> wrote:

> On 11.07.2017 20:50, Bill Ricker wrote:
> > On Tue, Jul 11, 2017 at 4:07 AM, Binarus <[email protected]> wrote:
> >>
> >> On 10.07.2017 20:14, Eric Brine wrote:
> >>> I don't understand the conditions. The law determines when the
> switching
> >>> of offsets from UTC happen, not some person. The switch doesn't happen
> >>> at 08:48:27 am in Chicago; it happens at 2am.
> >>
> >> This point of view is a bit U.S. centric. Indeed, you are describing how
> >> it *should* be, but
> >
> > We tend to use the timezone nearest us for examples because we're less
> > likely to be wrong and thence get dragged into discussing the example
> > instead of the concept.
> >
>
> Well, first of all, I did not want to insult or even criticize anybody.
> Please forgive me if my wording even made the slightest impression of
> doing so - regrettably, I am not a native English speaker.
>
> Actually, I am feeling the highest respect towards the experts who are
> helping with the time zone database updates, are bringing them to a
> machine readable form and are writing software modules which are dealing
> with the overwhelming bunch of time calculating oddities in an
> impressive manner. I am really very grateful for that and can't thank
> those volunteer experts enough.
>
> I just wanted to say that the statement "... the change happens at 2:00
> in Chicago ... " might not be sufficient for my case because I am trying
> to write a web application which deals with date and time calculations
> in local time zones around the world, and that I'd like the application
> to behave well (as far as possible) even in the weirdest cases.
>

Chicago was the OP's example. I'm not even American.

My point was that the time of change is not up to debate; it's in the time
zone db, so the information is available. It's not as arbitrary as I
thought the OP made it sound.

Others have pointed out this the time zone db can change with very little
notice since TZ definitions can change with very little notice.

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<div dir=3D"ltr"><br><div class=3D"gmail_extra"><br><div class=3D"gmail_quo=
te">On Wed, Jul 12, 2017 at 11:07 AM, Binarus <span dir=3D"ltr">&lt;<a href=
=3D"mailto:[email protected]" target=3D"_blank">[email protected]</a>&gt;</sp=
an> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;=
border-left:1px #ccc solid;padding-left:1ex"><span class=3D"">On 11.07.2017=
 20:50, Bill Ricker wrote:<br>
&gt; On Tue, Jul 11, 2017 at 4:07 AM, Binarus &lt;<a href=3D"mailto:lists@b=
inarus.de">[email protected]</a>&gt; wrote:<br>
&gt;&gt;<br>
&gt;&gt; On 10.07.2017 20:14, Eric Brine wrote:<br>
&gt;&gt;&gt; I don&#39;t understand the conditions. The law determines when=
 the switching<br>
&gt;&gt;&gt; of offsets from UTC happen, not some person. The switch doesn&=
#39;t happen<br>
&gt;&gt;&gt; at 08:48:27 am in Chicago; it happens at 2am.<br>
&gt;&gt;<br>
&gt;&gt; This point of view is a bit U.S. centric. Indeed, you are describi=
ng how<br>
&gt;&gt; it *should* be, but<br>
&gt;<br>
&gt; We tend to use the timezone nearest us for examples because we&#39;re =
less<br>
&gt; likely to be wrong and thence get dragged into discussing the example<=
br>
&gt; instead of the concept.<br>
&gt;<br>
<br>
</span>Well, first of all, I did not want to insult or even criticize anybo=
dy.<br>
Please forgive me if my wording even made the slightest impression of<br>
doing so - regrettably, I am not a native English speaker.<br>
<br>
Actually, I am feeling the highest respect towards the experts who are<br>
helping with the time zone database updates, are bringing them to a<br>
machine readable form and are writing software modules which are dealing<br=
>
with the overwhelming bunch of time calculating oddities in an<br>
impressive manner. I am really very grateful for that and can&#39;t thank<b=
r>
those volunteer experts enough.<br>
<br>
I just wanted to say that the statement &quot;... the change happens at 2:0=
0<br>
in Chicago ... &quot; might not be sufficient for my case because I am tryi=
ng<br>
to write a web application which deals with date and time calculations<br>
in local time zones around the world, and that I&#39;d like the application=
<br>
to behave well (as far as possible) even in the weirdest cases.<br></blockq=
uote><div><br></div><div>Chicago was the OP&#39;s example. I&#39;m not even=
 American.</div><div><br></div><div>My point was that the time of change is=
 not up to debate; it&#39;s in the time zone db, so the information is avai=
lable. It&#39;s not as arbitrary as I thought the OP made it sound.</div><d=
iv><br></div><div>Others have pointed out this the time zone db can change =
with very little notice since TZ definitions can change with very little no=
tice.</div><div><br></div><div>=C2=A0</div></div></div></div>

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