O.E. monað, from P.Gmc. *mænoth- (O.N. manaðr, M.Du. manet, Du. maand, O.H.G. manod, Ger. Monat, Goth. menoþs "month"), related to *mænon- "moon" (see moon). Its cognates mean only "month" in the Romance languages, but in Gmc. generally continue to
do double duty. Phrase a month of Sundays "a very long time" is from 1832 (roughly 7 and a half months, but never used literally).