How old is the skeleton

A visitor at the Royal Tyrell Museum asks a museum employee: "Can you tell me how old the skeleton of that T-Rex is?"

"It is precisely 60 million and three years, two months, and eighteen days old."

"How can you know that with such precision?!"

"Well, when I started working here, one of the scientists told me that the skeleton was 60 million years old ¨C and that was precisely three years, two months, and eighteen days ago..."