[tz] Astrakhan region got approval to change its time zone

[Paul Eggert]

Paul Goyette wrote:
> we should go ahead with the +0400 variant.  At
> least this way, there'll be only one new variant for people to absorb!

We'll need multiple variants even if we avoid 2-digit offsets, as there have 
been time zones that were not integral multiples of a minute. The classic 
example is Liberia from 1919 through 1972, which was 44.5 minutes behind 
Universal Time. We could use a 6-digit offset for this abbreviation, i.e., 
"-004430"; this would go a bit beyond what ISO 8601 and POSIX allow, though.

Such offsets are no longer in use, and the Liberia example need not impel us to 
use 6-digit offsets everywhere. By analogy, the existence of UT offsets like 
India's current "+0530" need not impel us to use 4-digit offsets everywhere.