köken: Inherited from Middle High German übermorgen, from Old High German ubar morgan, ubar morgana; equivalent to über- (“over, above”) + morgen (“tomorrow”). Compare Dutch overmorgen, Yiddish איבערמאָרגן (ibermorgn).
Nietzsche Erst das Übermorgen gehört mir
Dem Abschied von allem Möglichen des Morgens und des Übermorgens
köken: From birisi + gün. Cognates Compare Karachay-Balkar бюрсюкюн (bürsükün) /бюрсикюн (bürsikün), Kumyk бирисигюн (birisigün), Kazakh бүрсігүні (bürsıgünı), Nogai бирсигуьн (birsigün), Kyrgyz бүрсүгүнү (bürsügünü), Southern Altai бирсӱӱн (birsüün), Karaim birisikün etc., some of which mean 'the day before yesterday' and some - 'the day after tomorrow'.
From Old Georgian ზეგ (zeg), possibly borrowed from post-Classical Old Armenian *զէգ (*zēg), from զ- (z-, “to”) + *էգ (*ēg), a later form of այգ (ayg, “morning”); compare Old Armenian զ-այգ-ոյ (z-ayg-oy, “till tomorrow”), dialectal Armenian էգ-ուց (ēg-ucʻ, “tomorrow”). Note that Classical Old Armenian -այ- (-ay-) regularly develops into -է- (-ē-) before consonants in Middle Armenian and the…