For the brits

[Urbane Guerrilla]

Originally Posted by monster

Yes, it is. Although it is often adopted by theater fops wanting to appear more sophisticted, like so many other Brit phrases.

I'd argue that it is known and used everywhere in the English-speaking world. I've seen and used the phrase well before my present spate of community theater. Sixes and sevens refuse to match up until you arrive at the forty-twos. It's trouble, Monst, trouble.