Must be said in a Thick Irish accent, Used to express affection for a certain moment in time, or an event that you just witnessed take place.
Friend 1: "Haha, alright all the crew's here, let's start walking downtown."
Friend 2: "IT'S A GREAT DAAAY!"
Friend 2: "IT'S A GREAT DAAAY!"
by Gorilla Pimp January 11, 2009