Hmm, I enjoyed singing your song aloud, of course it might not be to your beat but it was enjoyable. Even though it's based off another song I really liked it.
The flow was a little bit rough at times but at other times it worked better than good. If you were trying to put in some rhyming it didn't work very well... so I'd keep away from rhyming in this song if your were trying for rhyming. Actually this song goes perfectly without rhyming.
Good work. Just add capitals... it's bugging me without them.
EDIT: Is this song based off "Closing Time" by Green Day... (I think that's the title... or one of Green Day's songs that has "Three Days" in it?)