[imp] UT date headers not displaying properly

[Jaap Winius]

Quoting Jan Schneider <jan at horde.org>:

>>     Date: Tue, 23 Oct 2007 07:15:07 UT
>
> "UT" is not a valid timezone.

According to RFC 2822, UT is a valid timezone, albeit an obsolete one (search
for "obs-zone"). However, that's not a reason not to support it.

Cheers,

Jaap