The Collaborative International Dictionary of English v.0.48:

Calends \Cal"ends\, n. pl. [OE. kalendes month, calends, AS.
   calend month, fr. L. calendae; akin to calare to call,
   proclaim, Gr. ??????. CF. Claim.]
   The first day of each month in the ancient Roman calendar.
   [Written also kalends.]
   [1913 Webster]

   The Greek calends, a time that will never come, as the
      Greeks had no calends.
      [1913 Webster]