that'll be the day

that'll be the day

English

Phrase

that'll be the day!

1. (idiomatic) Said in reply to something that one believes will never happen.

   I’m going to get into work on time today. — That’ll be the day!

Translations

said in reply to something that one believes will never happen

French: ça arrivera quand les poules auront des dents Russian: когда́ рак на горе свистнет (ru) (kogdá rak na gore svistnet)

Spanish: el día que la vaca vuele

See also

• a cold day in hell
• until the cows come home
• when hell freezes over
• when pigs fly