DST switching dates
72157.3334 at CompuServe.COM
Sat Mar 22 10:13:38 UTC 1997
Nathan Myers > INTERNET:ncm at cantrip.org wrote:
>Clearly the only sensible approach to time would be to leave the damn
>clocks alone, and change schedules to match reality. However, it's a
>waste of everybody's time and attention to discuss this here. We techies
>are constrained to chase after whatever foolish decisions are made in the
>parliaments and politburos of world. This list is about details of that
>Maybe there should be another list to help discover strategies to influence
>idiot politicians. I hope that those of you who are interested in the idea
>will create that list, instead of using this one.
The current list is divided many ways as to what relationship local mean time
(LMT) should have to local clock time (LCT). One the one hand we have persons
like yourself who advocate standard time throughout the year (at least I think
that is what you are advocating) and alternatively we have advocates for up to
three hours of year-round DST such as Peter Hullah, who stated that everyone
"should add two hours to their current standard time" all year round. (Since
he lives in France, that would be three hours ahead of local mean time.)
(A thought: has anyone here in favor of DST in REVERSE?)
Garrett Wollman > INTERNET:wollman at LCS.MIT.EDU wrote in reply to me:
>On 20 Mar 97 23:41:37 EST, Chris Carrier <72157.3334 at CompuServe.COM> said:
>>Unfortunately things seem to be going in the other direction, given the EU's
>>decision to copy the US/UK bad habit of ending DST on the last Sunday in
>>OCTOBER, by the end of which the sun is rising later than the large majority
>>of day-shift workers get up.
>And those of us who live in cities like Boston, which have ``night
>life'' rather than ``morning life'' think this is perfectly
DST rules should not be determined by cities such as Boston, but by cities on
the western edge of timezones such as Cleveland in the Eastern or Dallas in
the Central (and places like Indiana and West Texas should go back an hour
into their astronomically correct zone.)
Sue Ann Bowling > INTERNET:sbowling at gi.alaska.edu wrote:
>The dates of daylight savings shift, and the assymmetry between the spring
>shift (when we in Alaska are already pracitically going to bed in daylight)
>and October (when it's already dark when we're going home in the evening)
>have bothered me for years.
The problem in Alaska isn't DST but that ever since October 1983 most of the
state, except for Southeast, has been on DST all year with a 2 hour advance
during the DST period in the Lower 48.
>I wonder if the politicos who first devised the shift thought that solar
>symmetry was around the middle of the winter and summer?
It seems to have been a thing that evolved. When DST first went US-national
in 1918-9, it run from the last Sunday in March to the last Sunday in October.
When many states and localities started using it in 1920 in the absence of
national legislation, they shortened it by a month on each end, from the last
Sunday in April (a ridiculously late date in Lower 48 latitudes) to the (very
sensible) last Sunday in September. This went on until 1942-5 when DST was
national and year round for the war. It should be noted here that the War
Time Act of 1942 called for DST to last until six months after the end of the
war, but when the war did end in the summer of 1945 a bill was quickly passed
to end War Time on the last Sunday in September, 1945.
What I call the "October problem" started in Massachusetts when the
legislature there extended DST to the end of October, starting in 1954. (IMHO
they should have left September alone and started a month earlier if they
wanted an extended DST period.) The next year New York and the rest of New
England got on the bandwagon, and by 1962 most places on DST were ending on
the last Sunday in October. (A few, however, shortened the end to Labor Day -
- Minnesota was one.)
Then along came the Uniform Time Act of 1966 which set up the dates of the
last Sunday in April to October, nationwide. It should be pointed out that
when this bill was originally introduced it did not put the whole country on
DST but only stated that anyone using DST had to abide by April Sun=>24 to
October Sun =>25 switch dates. Unfortunately the bill was then rewritten to
put the whole nation on DST unless states exempted themselves. An amendment
to the bill reducing the DST period from Memorial to Labor Day unfortunately
failed; this was reintroduced in 1970 and also failed.
After the 1974-5 experience with a much earlier start to DST, bills were
introduced in each Congress from 1976 on to increase the DST period until in
1987, one passed to move the start date from the last to the first Sunday in
April. My position during those years was to support the earlier change if
and only if the ending date was moved back to the last Sunday in September.
In 1981 I was happy to see the EEC (later known as the EC, now known as the
EU) adopt last Sunday March-September for its continental members, hoping this
would inspire the UK and US to do likewise and create something like the
Livingston worldwide-switch-day proposal (which is what the UTA of 1966 was
and should have been). But alas, this was not to be.
>Anyway, a popular science article I wrote on the topic 10
>years ago is on the web at
><http://www.gi.alaska.edu/ScienceForum/ASF8/812.html>, pointing out some of
>the oddities of time zones here in our 60 degree wide state.
I used to write similar articles for the BARROW SUN and the ALEUTIAN EAGLE
1987-92 (when they folded). If you are interested I could send you one I
wrote in October 1988 commenting on the fifth anniversary of the consolidation
of time zones in Alaska five years earlier.
Eric Ulevik > INTERNET:eau at ozemail.com.au wrote:
>It is extremely unlikely that time zone rules will be simplified
>to make life easier for computers. For example: sunrise and sunset
>in Hobart vary sufficiently from Sydney that they are always going
>to want to have different summer time start/end dates. Another
>example: Adelaide has an offset of <hours>:30m from GMT.
Nor should they. Time zone rules should be set by wake-sleep patterns, not
the perceived need of the business community to have everyone on the same
time: (A fabulous letter to the London Times during the British Standard Time
period (1968-71) put it thusly: "We have 3000 telephone links between Britain
and the Continent. Why do we need to get 55 million people out of bed in the
dark to answer them?")
>Having said that, I have an idea for how to simplify time zone rules.
>A 'mean local time' can be calculated based upon location on the
>earth's surface. This time can be algorithmically biased to
>allow for daylight savings, smoothly varying over the year. Clocks
>can use GPS and the standard algorithm to calculate this time.
>Of course, this was the case before standard time, but transport
>and communications go faster these days.
Which is why it could never be practically adopted.
If I were at the Meridian Convention in Washington, DC, USA, in (I believe)
1881, where they settled on Greenwich as the meridian, (a good decision IMHO)
I would have advocated a planetwide version of what the German State Railways
were doing. They had time zones based on Berlin, with each zone 10 minutes in
time (2.5 degrees of longitude) apart. What I would have wanted would be such
a system of 144 time zones, 10 minutes apart, centered on Greenwich.
>The problem here is that administrative units - say Sydney -
>may wish to adopt a standard time, but then we end not
>having algorithmically determined time.
Actually the problem is that organizations which deal in a large area such as
railways and, in our century, broadcasters, need to have uniform time over a
large area. There were many standard 'railway times' before standard time was
introduced to reduce confusion in this area.
>3) Time near the poles probably needs a special case.
Would you believe the South Pole keeps DST? The first commander of the Pole
Station wanted to keep GMT, but discovered it was more convenient to keep the
time of their supply line; McMurdo Sound, which kept the same time as New
Zealand. Since NZ has had a seasonal time change since 1974, McMurdo follows
suit, and so does the Pole Station.
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