User blog comment:Curelove/changes brought by nick as from season 4 episode 18/@comment-97.77.46.197-20120717174603

I think you guys are reading the 'century' thing too seriously. When they described Tir Nan Og, they said it was on it's own dimension parallel to Earth. They did not say Tir Nan Og was on Earth or that it used Earth time. Go back to the earlier episodes were they were trying to figure out how to get there. The only way they could do it was through Roxy that first time and that was only because she was an Earth Fairy. Faragona told them she was the key.