Text 28215, 132 rader
Skriven 2012-04-22 10:50:42 av Roy Witt (1:387/22)
  Kommentar till text 28117 av Michiel van der Vlist (2:280/5555)
Ärende: TZUTC Kludge
====================
20 Apr 12 13:37, Michiel van der Vlist wrote to Roy Witt:

 RW>> And here DST begins on the 2nd Sunday in March and ends on the first
 RW>> Sunday in November.

 MvdV> But how boiut other countries? Not all countries have DST and the
 MvdV> transition times vary wildly. Try to figure it out for Mexico...

8^)

Mexicans still use the sundial to tell them what time it is...or a finger
for each 15 minutes between the horizon and setting sun will give them a
clue as to when to turn on the headlights, if they have any.

 RW>>>> Using my DX World Map posted on the wall over this PC, just
 RW>>>> knowing your country is close enough.

 MvdV>>> aparently not...

 MvdV> Plus that my DX world ma0 is over 30 years old. A lot has changed
 MvdV> since then.

Mine is from a year or two before we moved from San Diego to Texas. Maybe
ten years old.

 RW>> The time zones on the map don't follow local time zone lines, they
 RW>> follow degrees before and after UTC 0. i.e. the center of the -6
 RW>> hour coordinates is 90 degrees west of UTC 0, but -6 hours UTC
 RW>> begins closer to New Orleans than San Antonio, which is closer to 90
 RW>> degrees.

 RW>> Which doesn't reflect the true CST which begins on the Eastern
 RW>> border with Louisiana and ends somewhere in west Texas, putting El
 RW>> Paso, Texas in the Mountain Standard Time zone.

 MvdV> Same for other countries. Time zone bouderies usually follow
 MvdV> national borders, not line of longitude.

 RW>> I would  suspect the same is true of local time zones in Europe, to
 RW>> accommodate a convenience for heavily populated areas.

 MvdV> Of course. But if you look at the map, you can see that Spain is
 MvdV> MET and the UK is WET, despite the fact that Spain is directly
 MvdV> south of the UK. Portugal OTOH is WET.

Good to know. Historically, at one time or another, 0 degrees ran through
Paris but the Brits got their way, aaain.

 RW>>>> The time chart at the bottom of that map shows western Europe
 RW>>>> standard time is either 0 or 1 hour before 0.

 MvdV>>> Eh.. no. My country is not on Western European Time, it is on
 MvdV>>> Middle European time. +0100 in winter and +0200 in summer...

 RW>> Right. 0 UTC is in Greenwich, England and 0100 begins somewhere
 RW>> around 7.5 degrees east of there. i.e. South Africa is split up the
 RW>> middle by the 0100-0200 line at 22.5 degrees, but I'll bet the whole
 RW>> country is in one time zone.

 MvdV> It is. +0200

 RW>>>> Interesting is how Ireland is split up the middle, either 0 or
 RW>>>> -1...how they deal with that I don't know.

 MvdV>>> Your chart is wrong. All of Ireland is on the same time. Same
 MvdV>>> time as the UK.

 RW>> Which is a local time zone difference for convenience of the
 RW>> population.

 MvdV> As i said, time zones follow national bounderies rather than lines
 MvdV> of longitude. Only big countries like the US, Russia and Australia
 MvdV> have more than one time zone.

And the time zones in the US follow population and state lines.

 RW>>>> I know that your country is in the 0100 time zone. See above.

 MvdV>>> But how do you know?

 RW>> The map includes a close-up view of western Europe. Time zones are
 RW>> shown by a dotted line, which is self explantory in the "Legends"
 RW>> column.

 RW>>  ----------- Time Zone Boundry

 MvdV>>> Where do you get the information about the DST transition
 MvdV>>> times?

 RW>> That's a guessing game, but usually close to the same times as the
 RW>> transition takes place here, give or take a week or so...

 MvdV> You could be three weeks off in March (2nd Sunday, vs last Sunday).

If I really have to know, I refer to the USNO website.

 MvdV> En before 1996, you would be over a month off in fall. (last Sunday
 MvdV> in Sept vs first in November)

Or right on the night before by catching the DST announcement on local
radio or TV news...

 RW>> and just like Arizona (MST) there are probably places around the
 RW>> world that don't have DST.

 MvdV> There are LOTS of places that do not have DST.

AZ came to mind because Arizona (MST) and California (PST) are on the same
local clock-time when CA switches to PDST in the late fall...

 MvdV>>> Probably. There is also the matter of on-line bank transfers. I
 MvdV>>> just made a payment 5 minutes before the deadline. Had I not
 MvdV>>> used local time, I would have been late...

 RW>> I use paper...which is my choice.

 MvdV> To each his own. I have learned to appricate the almost
 MvdV> instantaneous electronic transfers.

I like to keep them guessing. Will he or won't he make the payment before
the due date?


                R\%/itt


  ... Only those who will risk going too far can possibly
  ... find out how far one can go ~ TS Eliot


--- Twit(t) Filter v2.1 (C) 2000-10
 * Origin: Roiz Flying \A/ Service * South Texas * USA * (1:387/22)