[Discuss] Abolish DST (was This year's Beowulf Bash is not for the lily-livered)

Kent Borg kentborg at borg.org
Mon Nov 22 14:55:41 EST 2021


On 11/22/21 10:36 AM, jc at trillian.mit.edu wrote:
> Some time back, I saw  a  fun  discussion  started  with  one  person
> arguing  for  year-round  EDT in New Enland, followed by someone else
> suggesting that instead, New England should switch to AST.   The  fun
> part was the quick realization that a lot of people didn't understand
> the difference, and got into rather nasty fights calling  each  other
> all sorts of insulting names.
>
> Since then I've often thought that this is a really good way to  mess
> up  such  discussions,  and  we  should all be trying it whenever the
> topic comes up.  ;-)

I love it! Ask those year-arounders whether they want EDT or AST, and 
then argue for the opposite.


Time is real simple. And very useful for predicting and scheduling and 
synchronizing stuff.

The very useful aspects mean we layer lots extra important stuff on top 
of it: where the sun will be in the sky, seasons, birthdays, religious 
holidays (haven't wars been fought over when is Easter?), precise 
durations, predictable decompositions, etc. And let's also change our 
clocks twice a year, in most but not all places, and let's do it on 
dates which are not consistent from one participating place to place nor 
from year to year. Also allow local officials to change timezone for 
arbitrary reasons, changing their minds form time to time, including 
fractional timezones!

Which means time is no longer simple. But multi-year mortgage and bond 
calculations still need to be correct.

At first glance time still looks simple, and that's when people start 
writing bugs.

When I was born the second was defined as a specific fraction of a day, 
which meant the length of a second was variable depending on what the 
earth was up to. When I was a little kid the second was redefined to be 
of a fixed length, and it was the *day* that became of variable length; 
the second was heretofore defined as rock-solid.

Nope. Youngsters know time is simple and still write code that assumes 
things are today as they were when I was born: a second is a fixed 
fraction of a day.

So because programmers think time is simple, we have a fairly new 
(fuzzy) Google definition of the second. Mostly it is dang precise and 
stable, but every year or so, it starts to slew wildly away from its 
usual precise duration and then slew wildly back, all to avoid leap 
seconds that would trigger bugs where programmers thought they knew that 
a minute would always have 60-seconds. (Silly of them.)

I say fuzzy because I am pretty sure how and when the slewing happens is 
not well defined, is probably not consistent from one leap second to the 
next. And this odd time standard is distributed via NTP, which was not 
intended to distribute a non-stable reference, so the result is going to 
be a mess from any time-standardization perspective. But at least it 
won't trigger any brand new 60-second-per-minute bugs.

And god help any programs that crazily assume a second is of fixed 
length, but then get hooked up to Google time.

Time is complicated.

-kb







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