Contrary to popular belief, the International Date Line is not a phone number that people can call so that they can speak on the phone with potential significant others from exotic locales such as Thailand, Spain, Siberia, and New Delhi.
Rather, the Line was created to give people who live by the calendar a headache. Here's why:
If a traveler happens to be jaunting around the world -- or around a certain part of it filled with a small body of water called the Pacific Ocean -- and that traveler happens to cross the Line going westbound, then, at that very moment, without fail, the next day is lost.
Okay, that may not be clear enough. So let's hypotheticalize.
Billy Jack is in a train going five hundred miles an hour, headed from Chicago to New Orleans, while Billy Mac is in a train going two hundred and thirty miles an hour, headed from New Orleans to Chicago. At what city does Billy Jack's train smack headlong into Billy Mac's train?
Wait, wrong example. Let's try another.
Billy Jack is on a steamer headed west from San Francisco to New Delhi (despite the fact that New Delhi is well-inland, Billy Jack hopes his steamer will make it anyway). He happens to know that for every 15 degrees of longitude that his ship travels, he has to set his watch back an hour. It's just like the rest of us have to do every Fall, when Daylight Savings Time kicks in (or when it turns off -- I can never remember which is which. Except in Arizona, where they decided that the whole Daylight Savings Time thing was a fad and would eventually go away of its own accord).
However, when Billy Jack gets to a certain spot marked on the planet by a line of floating buoys, he has been told that he will have to set his watch FORWARD an entire day.. (To clarify, it's "buoys," not "boys," even though "buoys" is how "boys" is pronounced in the South, where Billy Jack is from. Either way, Billy Jack soon discovers that someone has tricked him. There are neither buoys nor boys floating around in the water, and he is still expected to set his watch forward a day).
Billy Jack is confused. He's been setting his watch BACK, but now he must set it forward. Not only that, but he was also supposed to wire a message to his wife on Thursday (our story is taking place in the 30s, you see, when they had things like "wirelesses" and "watches" rather than "cell phones" and "wrist-dependant temporal calculating devices"). Now there isn't going to BE a Thursday; the week is going to go straight from Wednesday to Friday.
Knowing how his wife is about things like that, Billy Jack is concerned about the safety of his golf clubs.
Meanwhile, Billy Mac is on a steamer headed east-bound from New Delhi to San Francisco (having discovered that New Delhi was pretty far inland and not wanting to walk quite that much). Billy Mac and Billy Jack (cousins) had previously made plans to wave at one another as their steamers passed each other. Alas, now Billy Mac learns that even though he has been setting his watch forward an hour for every fifteen degrees east he's traveled, once the ship crosses a line of boys floating in the water (See Above), he'll have to set it BACK an entire day. Wednesday is about to become Wednesday again.
The result is that the steamers never manage to cross paths. At least as far as Billy Jack and Billy Mac can tell.
The situation becomes even more complicated if Billy Jack were to continue cruising on around the world (having discovered that New Delhi was indeed pretty far inland and, not wanting to walk quite that much). He gets back home and realizes that he's a day younger than he was when he left. Should he tell people? Should he rearrange his plans so that his birthday happens a day later than it normally would?
Poor Billy Jack.
On top of that, once home, he finds that his wife has thrown his golf clubs in the trash compactor (which they may or may not have had in the 30s). Not that it matters, Billy Jack decides. He wouldn’t have known when tee-time was, anyway.
In a follow-up interview, Billy Jack and Billy Mac told the author that they never saw one another again because Billy Mac was always two days behind Billy Jack. This despite the fact that the author was interviewing them at the same time and in the same room.