The sqlite3 timestamp conversion between unixepoch and localtime can't be done according to the timezone setting on the machine automatically.

[Chris Angelico]

On Wed, Sep 1, 2021 at 7:54 AM <2QdxY4RzWzUUiLuE at potatochowder.com> wrote:
>
> On 2021-09-01 at 07:32:43 +1000,
> Chris Angelico <rosuav at gmail.com> wrote:
>
> > On Wed, Sep 1, 2021 at 7:17 AM <2QdxY4RzWzUUiLuE at potatochowder.com> wrote:
>
> > > What about Phoenix?  In the winter, it's the same time there as it is in
> > > San Francisco, but in the summer, it's the same time there as it is in
> > > Denver (Phoenix doesn't observe Daylight Saving Time).
> >
> > I prefer to say: In winter, San Francisco (or Los Angeles) is the same
> > as Phoenix, but in summer, Los Angeles changes its clocks away, and
> > Denver changes to happen to be the same as Phoenix.
>
> Not exactly.  Sort of.  Phoenix and Denver are both in America/Denver
> (aka US/Mountain), but only Denver observes DST.  San Francisco and Los
> Angeles are both in America/Los_Angeles, and both observe DST.

America/Phoenix is a separate time zone from America/Denver. During
winter they represent the same time, but during summer, Phoenix
doesn't change its offset, and Denver does.

(San Francisco isn't an IANA timezone; the city precisely follows Los
Angeles time.)

> > ... I think Egypt (Africa/Cairo) is currently in the lead for weirdest
> > timezone change ...
>
> Yeah, I read about that somewhere.  Remember when the Pope declared that
> September should skip a bunch of days?

Well, that's from transitioning from the Julian calendar to the
Gregorian. The same transition was done in different countries at
different times. The Pope made the declaration for the Catholic church
in 1582, and all countries whose official religion was Catholic
changed at the same time; other countries chose their own schedules
for the transition. Notably, Russia converted in 1918, immediately
after the "October Revolution", which happened on the 25th of October
on the Julian calendar, but the 7th of November on the Gregorian.

> Way back in the 1990s, I was working with teams in Metro Chicago, Tel
> Aviv, and Tokyo (three separate teams, three really separate time zones,
> at least two seaprate DST transition dates).  I changed my wristwatch to
> 24 hour time (and never looked back).  I tried UTC for a while, which
> was cute, but confusing.

I tried UTC for a while too, but it became easier to revert to local
time for my watch and just do the conversions directly.

Perhaps, in the future, we will all standardize on UTC, and daylight
time will be a historical relic. And then, perhaps, we will start
getting frustrated at relativity-based time discrepancies ("it's such
a pain scheduling anything with someone on Mars, their clocks move
faster than ours do!").

ChrisA