UGT (abbr.): Universal Greeting Time.
UGT is convention initially established in #mipslinux on irc.openprojects.net (now irc.freenode.net) but slowly taking over the world. It states that it is always morning when person comes into a channel, and it is always late night when person leaves. Local time of any member of channel is irrelevant. Resistance is futile. Your ass will be laminated. (geoman is exception to this rule - his ass will be fried instead).
Used as follows:
Good (UGT) Morning, Everyone! or good morning (ugt) (on entry to channel).
Good (UGT) Night - when leaving it.
The idea behind establishing this convention was to eliminate noise generated almost every time someone comes in and greets using some form of day-time based greeting, and then channel members on the other side of the globe start pointing out that it's different time of the day for them. Now, instead of spending time figuring out what time of day is it for every member of the channel, we spend time explaining newcomers benefits of UGT.