Memory test of an old man

The doctor says to the second man, “It’s your turn.”

What is three times three?” “Tuesday,” replies the second man.

The doctor says to the third man, “Okay, your turn. What’s three times three?”

“Nine,” says the third man.

“That’s great!” says the doctor. “How did you get that?”

“Simple,” says the third man. “I subtracted 274 from Tuesday.”