In a month of Sundays

Pro Tip 1/3

Improbability

Use the phrase to express that an event is extremely unlikely to occur.

He's so stubborn, he won't apologize in a month of Sundays.

Pro Tip 2/3

Exaggeration

The phrase is often used for hyperbolic effect, not to be taken literally.

You could wait in a month of Sundays, but you still wouldn't see a bus here.

Pro Tip 3/3

Humorous Effect

Sometimes it's employed humorously to highlight the extent of a delay or inaction.

I'll grow old and grey waiting for her in a month of Sundays!