forever and a day

Possibly a folk-etymological alteration of forever and ay.[1]

forever and a day (not comparable)

1. (idiomatic) For a very long or seemingly endless time.

   Synonyms: forever and ever, forever and forever, (archaic) forever and ay

   I'll love you forever and a day.

   • c. 1590–1592 (date written), William Shakespeare, “The Taming of the Shrew”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act IV, scene iv], page 225, column 2:

     If this be not that you looke for, I haue no more to ſay, / But bid Bianca farewell for euer and a day.

   • 2018 February 2, Alejandro Zambra, “Remembering Nicanor Parra, the Almost Immortal Chilean Poet”, in The New Yorker‎, New York, N.Y.: Condé Nast Publications, →ISSN, →OCLC, archived from the original on 2023-06-02:

     I went to the front yard, talked for maybe two more hours with Colombina and Rosita, his caretaker, and then we had to leave, but Nicanor still had enough material for forever and a day.

   • 2023 November 17, The Tonight Show Starring Jimmy Fallon‎, episode 1878, spoken by Scarlett Johansson:

     Honestly, I had acne forever and a day and just struggled to find a routine that addressed my sensitive skin and so I made it!

• “forever and a day”, in Dictionary.com Unabridged, Dictionary.com, LLC, 1995–present.
• “forever and a day”, in Collins English Dictionary.
• “forever and a day”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present.