[conspire] "Time zones exist to make programmers' lives miserable" ...

[Rick Moen]

Quoting Nick Moffitt (nick at zork.net):

> The reasoning is roughly that if California should suddenly come to
> its senses and stop fiddling with the clocks twice a year, your San
> Francisco server would still be set to the correct wall time
> year-round with `America/Los_Angeles`, while `PST8PDT` would become a
> way of saying "I know you think you're right, but I want to move High
> Noon to 1pm for half the year even though we stopped doing this years
> ago."
> 
> Of course if California did this and Oregon and Washington kept on
> using PDT, people would have to rush to change their TZ to
> `America/Seattle` or something until everyone got on board.  So it's
> not the most robust argument.

Well argued, sir.  Yes, I _was_ thinking along those lines, somewhere
over the last couple of days, but plowed through quite a lot of material 
about timezones on *ix and drew a blank on that, when suddenly trying to
address Fred Brockman's question.

The *ix TZ database files show the scars of past timezone idiocy, like
the fact that _eight_ towns in Indiana still have distinct entries:

$ tzall | grep Indiana
America/Indianapolis
America/Indiana/Marengo
America/Indiana/Knox
America/Indiana/Vevay
America/Indiana/Indianapolis
America/Indiana/Vincennes
America/Indiana/Petersburg
America/Indiana/Winamac
America/Indiana/Tell_City
$

...while neighbouring, larger, more-urbanised Illinois 
has _one (America/Chicago), and Ohio and most other midwestern states
have none.  I attribute this to the past, largely fixed, Indiana
timezone situation prior to 2006.  Parts of the state were on Central
Time, other parts on Eastern Time, and there was county-by-county
variation about whether to observe daylight saving time or not.

So, without detailed local knowledge, if you drove across Indiana at
that time, you could easily be mistaken about what time it now was upon
crossing a county line -- which fans of _The West Wing_ may recall was a 
plot point:

  Supporters of daylight saving time and a common time zone in Indiana
  often claim Indiana must adopt the time-keeping system of the Eastern
  United States to preserve interstate business with that region. Some
  believe that Indiana businesses have lost hours of productive time with
  out-of-state colleagues because the time quirks are too confusing to
  keep track of on a daily basis.  The confusion caused to outsiders
  featured prominently in the plot of an episode of The West Wing in which
  presidential aides unfamiliar with Indiana's non-observance of DST miss
  their return flight to Washington, D.C., on Air Force One and express
  consternation with the variances in the state's time measurement.

https://en.wikipedia.org/wiki/Time_in_Indiana#Controversy

The 2006 reform involved a statewide law requiring that all counties
implement a single daylight time schedule.

https://en.wikipedia.org/wiki/Time_in_Indiana#tz_database shows the
current situation:  The many named towns used as labels for database 
entries doubtless used to reflect the former county-by-county madness 
-- and now point to far fewer real differences but (as your point
suggests) could be used to track such differences again, if necessary.