Which way do I cross the International Date line to go back in time?
In the book, Around the World in 80 Days (or click here for the pod cast) you cross going East to go to the next day. So, you have to go West to go back a day. However, you don't get to go back in time. Time continues to march forwards the entire trip. Still, if I had to do it over again, I might have arranged to have my honeymoon on a ship going West crossing the Pacific, going around the world, oh, and with an extra holiday weekend, and, well, I'll think of something else.
Why have a date line?
In the book, the main characters go around the world to the East. As they go, they must set their watches forward. Well, Verne has one character, Passepartout, keep London time on the trip. When he's half way around the world, his 12 hour watch matches the local time. He's all excited. This is just a hint at what saves the day, so to speak, at the end of the book. But if they did set their watches forward, they'd have set it forward a full day by the time they made it around the world. Now if it were a calendar watch, would it have the wrong date? You bet. That's because they'd have advanced the date by an extra day, which certainly didn't happen in London.
I know what you're thinking - "I don't have time for this".
Want to go back in time? Go West young man.
No, this is not a phenomenon that can be used to implement a Day After Pill For Men. However, this product as already been invented. It changes your blood type.