The concept behind the IDL (though not the IDL itself, which did not yet exist) appears as a plot device in Jules Verne's book "Around the World in Eighty Days" (1873). The main protagonist, Phileas Fogg, travels eastward around the world. He had bet with his friends that he could do it in 80 days. To win the wager, Fogg must return by 8:45 pm on Saturday, 21 December 1872. However, the journey suffers a series of delays and when Fogg reaches London, it's 8:50 pm on Friday, 20 December, although he believes it's Saturday, 21 December and that he has lost the wager by a margin of only five minutes. The next day, however, it is revealed that the day is Saturday, not Sunday, and Fogg arrives at his club just in time to win the bet. Verne explains: