one of these days is none of these days

one of these days is none of these days

A response to someone who says they will do something "one of these days" implying that one does not believe they ever will. A: "One of these days, I'm going to start getting serious about working out!" B:" Yeah, one of these days is none of these days, so I won't hold my breath."
See also: days, none, of, one, these
Farlex Dictionary of Idioms.

One of these days is none of these days.

Prov. If you say you will do something "one of these days," you probably do not seriously intend to do it, and therefore it will not get done. Alan: When are you going to fix the garage door? Jane: One of these days. Alan: One of these days is none of these days. Jill: One of these days, I'll pay you the money I owe you. Jane: One of these days is none of these days.
See also: days, none, of, one, these
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • for days on end
  • days on end
  • days running
  • for (some) days running
  • days hence
  • bygone
  • bygone days
  • end your days/life
  • heavenly days
  • the old days