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Re: [tlug] Ubuntu 13.10 clock problems

Bruno Raoult writes:

 > As I live in France, where there is DST change, localtime is
 > absolutely a no-go.

All hardware clocks keep time in seconds since the epoch.  Epochs are
well-known and do not change over time, but there are two in common
use: UTC and local time.  Let your clock's battery run down and then
start your computer.  If it starts by displaying time 0:00:00, you're
either on UTC or in the GMT zone (and it doesn't matter which, the
hardware can't tell the difference).  If it starts at some other hour,
you're on localtime.  You can accurately predict what hour from the
time zone where you bought the computer.

So there's really no problem here.  DST is irrelevant.  By the time
boot has proceeded far enough to worry about these issues, the
timezone library is available.  It will handle DST and such blips
(leap seconds, anyone?) based on the (integer) number of seconds since
the appropriate epoch.  (Note that in the U.S., where the practice of
localtime clocks originated, there were no times zones observing DST
on January 1, 1970, so there aren't any blips in the 24 hours that
matter, and there never will be.)

The problem here is simply that the vast majority of personal
computers sold are preconfigured to local time by the OEM OS (ie,
Windows), and a not insignificant number of those continue to have
Windows installed even though a POSIX OS is also installed.  Ubuntu
apparently has decided to ignore that fact, and force UTC for the
"convenience" of the customers.

It apparently believes that customers lack the knowledge and skill for
setting a clock, and need to have their clocks fixed when they are
demonstrably not broken.  Yuck.

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