An Etymological Dictionary of the German Language/Annotated/bis

by Friedrich Kluge

bis, conjunction, adverb, ‘until, as far as,’ from Middle High German biȥ (for which unze, unz most frequently occur); in Old High German it was perhaps biaȥ, i.e. bis is a compound of bĭ (see bei, Gothic bĭ) and aȥ (Old High German aȥ, ‘to,’ Gothic at, Latin ad); biaȥ became biȥ, ‘until’ Earlier Modern High German has a variant bitze, bitz, which likewise arose from an older bi and ze, ‘to.’ Similarly Modern High German unz is composed of unt (Gothic und) and ze. —