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

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From:
Eric Brine
Date:
July 12, 2017 16:40
Subject:
Re: TimeZones and politics Re: How to tell (in advance) if adate-time is ambiguous?
Message ID:
CALJW-qE8kYcK4SL+JmhMb-EaP-_jQtsYRN++yO2Dg__bRPdbqg@mail.gmail.com
On Wed, Jul 12, 2017 at 11:07 AM, Binarus <lists@binarus.de> wrote:

> On 11.07.2017 20:50, Bill Ricker wrote:
> > On Tue, Jul 11, 2017 at 4:07 AM, Binarus <lists@binarus.de> 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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