[tz] 'date -u' should say "UTC", not "GMT"

[Paul Eggert]

On 06/24/2014 02:34 PM, Clive D.W. Feather wrote:
> Paul Eggert said:
>>> >>UTC, yes.  UT?
>> >UT a.k.a. Universal Time" is deliberately ambiguous: it refers to all
>> >the UTx variants together.
> Are you sure of that?

It depends on who you talk to, but that's the sense I intended.  You can 
see similar usages in the Collins English dictionary and in Wikipedia:

http://en.wikipedia.org/wiki/Universal_Time#Versions

http://dictionary.reference.com/browse/universal-time

I take your point that some sources are stricter, and say that UT must 
be UT0 or UT1 (or maybe UT1R or UT2...), so I suppose it's yet another 
term that is controversial to some extent.