til the cows come home

till the cows come home

For a very long, indefinite amount of time; forever. You can wait till the cows come home, but you'll never see that law passed in this country! My wife was talking on the phone with her sister till the cows came home last night!
See also: come, cow, home, till
Farlex Dictionary of Idioms.

(un)til the cows come home

Rur. until the last; until very late. (Referring to the end of the day, when the cows come home to be fed and milked.) We were having so much fun that we decided to stay at the party until the cows camehome. Where've you been? Who said you could stay out till the cows come home?
See also: come, cow, home, til
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

till/until the ˈcows come home

(informal) for a long time, or for ever: You can talk till the cows come home, but you’ll never persuade me to go with you!
See also: come, cow, home, till, until
Farlex Partner Idioms Dictionary
See also:
  • not until the cows come home
  • till the cows come home
  • till/until the cows come home
  • until the cows come home
  • doomsday
  • till/until kingdom come
  • till doomsday
  • till kingdom come
  • until doomsday
  • until kingdom come
References in periodicals archive
As for her plans for 2013, Cheryl says she is trying not to make too many plans: "You can plan 'til the cows come home and then the cows never show up."
Cheryl Cole talks 2013 plans, documentaries and Tre Holloway
So, "'til the cows come home" could be as little as a few hours or as long as a year or more.
Metaphor menagerie: country cliches conceal nuggets of truth
You can troll his words for "what he's really thinking" 'til the cows come home. Has he invited you to the mall or bought you a burger or kissed you recently?
He's so into you ... or is he? Five foolproof, rarely wrong clues you can use right this very second to figure out if your crush digs you ..
Just plug it in, squeeze the trigger and till 'til the cows come home. It's surprisingly powerful but still easy to guide and control, and the handle folds up, so it only sips at precious storage space.
Electric mini tiller
But you can't eat it 'til the cows come home and expect your thighs to stay "fat-free."
Low-fat losers & winners
Play Hide-and-Seek 'til the cows come home. Quack away your summer leading rounds of Duck-Duck-Goose.
What's Your Summer Fun Style?