Is it same as saying "one more day?" I don't think I've seen people say "one day more" before.

Rebecca

Yes, this is a more old-fashioned way of saying "one day more" - it would sound awkward in today's modern context. Note that lyrics and older literature (like poems or plays) take more liberties with the way they express things. For writing and conversation today, "one more day" is always more preferable. Ex: I wish I could spend one more day on vacation. Ex: Just one more day until the weekend!