An Etymological Dictionary of the German Language/Annotated/Abend
Abend, masculine, ‘evening,’ from the equivalent Middle High German âbent (âbunt); Old High German âband, masculine; corresponding to Old Saxon âƀand, Dutch avond, Anglo-Saxon œ̂fen, ‘evening,’ whence English eve; also the derivative Anglo-Saxon œ̂fning, English evening (compare morning); Old Icelandic aptann; similarly Gothic andanahti, original sense ‘forenight,’ and sagqs, literally ‘setting.’ The SEurop. term corresponding to Greek ἕσπερος, Latin vesper, is non-Teutonic (compare West and Winter). A verb aben (ooben), ‘to grow dusk,’ adduced from the Swiss dialects to explain Abend, can be none other than a later derivative of Abend. Moreover, Abend (base êp-) can scarcely be connected with ab (base apo), as if Abend were the waning period of the day. According to old Teutonic notions, the evening was regarded rather as the beginning of the following day. See Sonnabend and Fastnacht.