ad kalendas Graecas*: Meaning and Definition of

ad ka•len•das Grae•cas

Pronunciation: (äd kä-len'däs grī'käs Eng. ad k&schwa-len'd&schwas grē'k&schwas), [key]
— Latin. Latin.
  1. at no time; never: from the fact that the Greeks did not reckon dates by calends.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.