I only listened to the song once, yesterday, but struck me this morning that it is kinda a rip off (and a B-version, at that) of Happily Ever After from Once Upon A Mattress.
I like it, but think about this: the song also has the phrase, "It Won't Be Long Now" in it a lot, so if it was called "It Won't Be Long Now" instead of "I Know It's Today", then there would be two shows on Broadway with a song called "It Won't Be Long Now" in them (in case you're not familiar with "In the Heights", there's a song in that called "It Won't Be Long Now").
Greetings from Helsinki! (I'm in Helsinki visiting my Finnish friend Pilvi for 4 days, because flights from Oslo to Helsinki are cheap and quick with Finnair).
