Why does Fogg give the time as "nineteen hundred and twenty hours, or a hundred and fifteen thousand two…

“All right,” said Mr. Fogg; and, turning to the others, he continued: “I have a deposit of twenty thousand at Baring’s which I will willingly risk upon it.”

“Twenty thousand pounds!” cried Sullivan. “Twenty thousand pounds, which you would lose by a single accidental delay!”

“The unforeseen does not exist,” quietly replied Phileas Fogg.

“But, Mr. Fogg, eighty days are only the estimate of the least possible time in which the journey can be made.”

“A well-used minimum suffices for everything.”

“But, in order not to exceed it, you must jump mathematically from the trains upon the steamers, and from the steamers upon the trains again.”

“I will jump—mathematically.”

“You are joking.”

“A true Englishman doesn’t joke when he is talking about so serious a thing as a wager,” replied Phileas Fogg, solemnly. “I will bet twenty thousand pounds against anyone who wishes that I will make the tour of the world in eighty days or less; in nineteen hundred and twenty hours, or a hundred and fifteen thousand two hundred minutes. Do you accept?”

“We accept,” replied Messrs. Stuart, Fallentin, Sullivan, Flanagan, and Ralph, after consulting each other.

“Good,” said Mr. Fogg. “The train leaves for Dover at a quarter before nine. I will take it.”

“This very evening?” asked Stuart.

“This very evening,” returned Phileas Fogg. He took out and consulted a pocket almanac, and added, “As today is Wednesday, the 2nd of October, I shall be due in London in this very room of the Reform Club, on Saturday, the 21st of December, at a quarter before nine p.m.; or else the twenty thousand pounds, now deposited in my name at Baring’s, will belong to you, in fact and in right, gentlemen. Here is a cheque for the amount.”