> there was no need to  bless real 3-digit time
> zones for  the corresponding countries.
> So we got  what the US  Army had
> allocated,
 
... except that it *wasn't* what the US Army had allocated.  I have to
laugh.  Seriously, the task of picking 3-letter codes is a national,
rather than international, one.  Just look at zone -0400, which North
Americans tend to call Atlantic Standard Time, but which includes such
nations as Equador (on the Pacific coast).  I seem to recall that
RFC733 allowed AST and a few others, but that tended to imply that
there would eventually be as many as 24+24 international standard zones,
and I can sympathize with a desire to avoid having to choose among
CET, MEZ, NST (Nigerian Standard Time), and a host of others.  I'll
cheerfully admit that blessing only the continental US time zones plus
GMT is decidedly unfair (cheerful because it doesn't inconvenience me!),
but I can't imagine a scheme that would make everybody happy.
 
>  alternatively we can code  things like
> '+0100', but  that's more than  3 characters
 
VM Mailer has a feature nowadays of translating "+nn" into "+nn00"
for mail headers it generates, and individual MUA's could easily
adopt the same capability.
 
> everybody  knows that the GMT  offset is never a  multiple of 60
 
Just for the record, there are places where the offset is *not* a
multiple of 60 minutes.  Newfoundland and Guyana (or is it Suriname?)
come immediately to mind.  Then there is Arab time, which traditionally
is a variant of local solar time.
 
> I guess the  only "legal" solution for me now is  to load my TOD
> clock with US time and use EDT :-)
 
Ah, but there's always GMT!  Personally, I don't mind the present state
of anarchy.  I get a chuckle out of the gloriously unspecific "LCL" time
zone.  I'm reminded of Flanders & Swann, who said, "I like my clock 20
minutes fast.  Do you?"
                                       John