Re: TimeZone trouble

Shane McCarron wrote:
>Cairo does this too.  I used to use midnight local time to determine  
>what 'day' it is.  That would mean the application would fail for an  
>hour in some timezones.  I changed to using some other time...  23:58 I  
>think.  This might fail somewhere too, but nowhere I have found.

Among others, Pacific/Enderbury (Phoenix Islands, part of Kiribati)
on 1995-01-01.  The *entire day* didn't exist in local time, because the
zone moved westward across the International Date Line (or, equivalently,
moved eastwards by 24 hours).  It went from UT-11h to UT+13h.

Many Pacific locations have switched sides of the IDL, some of them
more than once, and this results in a duplicated or omitted day.
Most famously Alaska switched, eastward, when it was purchased by the US.
The calendar day was duplicated, but duplication of the nominal calendar
date was avoided by simultaneously switching from the Julian Calendar
(as used by Russia) to the Gregorian Calendar (as used by the US).

-zefram