that'll be the day


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that'll be the day

Said of something that is unlikely to happen. Good fortune? Happening to me? Ha, that'll be the day!

That'll be the day!

Inf. It will be an unusually amazing day when that happens! Bill: I think I'll fix that lamp now. Andy: When you finally get around to fixing that lamp, that'll be the day! Sue: I'm going to get this place organized once and for all! Alice: That'll be the day!

that'll be the day

That will never happen, that's very unlikely, as in You think I'll win the lottery? That'll be the day! Presumably this phrase is short for that will be the day worth waiting for, but it is nearly always used ironically, as in the example. [Mid-1900s]

that'll be the day

COMMON People say that'll be the day to show that they think that something will never happen. `He says he's going to decorate his house.' — `Hah. That'll be the day.'

ˈthat’ll be the day

(spoken, ironic) used for saying that something is unlikely: ‘When I’m rich, I’ll buy you a new car.’ ‘That’ll be the day!’
References in periodicals archive ?
That'll Be The Day is renowned for its work with worthy causes, and is currently supporting the Make-AWish Foundation UK.
These included That'll Be The Day by Buddy Holly and The Crickets, Jailhouse Rock by Elvis Presley, Sealed With A Kiss by Brian Hyland and Bony Moronie by Larry Williams.
We first performed That'll Be The Day in Butlin's, Minehead.
Rock Around With Ollie Vee Another notable rockabilly classic, this track was written by Sonny Curtis and originally featured on Buddy's renowned That'll Be The Day album.
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That'll Be The Day is the nation's favourite rock'n'roll show, packed with all the pop hits of the 1950s, 60s and 70s.
The Daily Mail said "What a great value for money show That'll Be The Day is not to be missed
The origins of That'll be The Day can be traced back to 1985.
Here's what fans can expect this Saturday: BUDDY HOLLY: That'll Be The Day, Peggy Sue, Oh Boy, It's So Easy, Heart-beat, It Doesn't Matter Anymore, True Love Ways, Raining in my Heart EVERLY BROTHERS: Bye Bye Love, Wake up Little Susie, All I Have to do is Dream, Cathy's Clown, Walk Right Back, Temptation, Cryin' in the Rain, The Price of Love CONNIE FRANCIS: Who's Sorry Now, Stupid Cupid, Lipstick on Your Collar, Where The Boys Are, Everybody's Somebody's Fool, Mama AND FROM THE EVENING'S COMPERE THE BIG BOPPER: Chantilly Lace, Running Bear
With irreverent send ups of all the top stars and over 80 songs and 400 costumes, That'll Be The Day is a riot of colour,music and fun with a real feel- good party atmosphere.
Let us just say that'll be the day, and then let sleeping dogs lie.
THE promise of nostalgia - in the form of classic gold musical hits from the 50s to the 80s - draws people back to That'll Be The Day time and time again.
Buddy tells the story of Buddy Holly, the legendary songster behind That'll Be The Day and Raining In My Heart.
Rock 'n' roll touring production That'll Be The Day has got together with broadcaster and songwriter Mike Read to record the CD Dark Horse.