(idiomatic, Britain) (of a person) in reality; in fact; when it comes down to it. / (idiomatic, Britain) (of a topic) plainly; in plain English; at its most basic level.

Alternative form of buy when it snows, sell when it goes

(business, stock market, chiefly northern US and Canada) Stock market securities can be expected to increase in value to a greater degree in the cold winter months from November through April than in the warm months from May through October, and profit-minded investors should manage their portfolios accordingly.

(usually in the past tense) To have known a famous person before he or she was famous.

simple past tense of know someone when

Ellipsis of when the cat's away, the mice will play.

Alternative form of when all is said and done

Unfortunate events occur in streaks or clusters, often in short periods of time.

(idiomatic) Never.

(idiomatic) When the pressure is on; when the situation is urgent or critical