GUG is a quite new element of Internet slang used mainly on IRC networks to accommodate the need for a universal greeting not depending on the geographical location of the speaker.
The number of IRC channels speaking a single language (mostly English or Spanish) but frequented by chatters from diverse locations and diverse time zones, has grown a lot. Saying "GUG" instead of a usual greeting will help discussions stay abstract from geography and other issues not related to channel's topic, assuming a universal time zone for the channel.
GUG is a “Hello!” in the Internet world.
UTC - coordinated universal time
