Interesting question. To understand the answer, we have to understand where time zones came from in the first place.

Up until the mid-19th century, major cities would set their local time by when the sun was at its highest point in that particular city. It was called local mean time. For example, when it was 12 p.m. in New York City, it was 12:23 p.m. in Boston. With the onset of railroads and rapid transit from place to place, local mean time made things increasingly more difficult, since trains arriving from a certain city would be arriving at each stop’s local time. Needless to say, people were confused.

So began the creation of an international standard of time. Delegates from 27 countries met at what was known as the Meridian Conference, and decided to implement a plan outlined by Sir Sandford Fleming (a railway planner and engineer). The plan looked like this: The world would be divided into 24 time zones based on the 24 hours in each day. Each of the time zones would be defined by a meridian, or a north-south line running from the North Pole all the way to the South Pole. All of the times were set according to Greenwich Mean Time (using the prime meridian that runs through Greenwich, England), which later became known as Coordinated Universal Time (UTC). So for example, Eastern Standard Time became UTC -5 hours. Eastern European Time became UTC +2 hours.

So why are some cities 30 or 45 minutes off? That has largely to do with the politics in each of those places. For example, in New Delhi, India, they found themselves halfway between two meridians, and therefore decided to be 30 minutes between each, as opposed to adopting one time or the other.

Also, even though India’s expansive regions cross two time zones, all of India carries the same time. Even quirkier? All of China, which spans an impressive five time zones, has the same time, which is UTC +8 hours. That means that in some areas of China, they have dark mornings and light nights. Go figure.

The BBC posted an interesting piece about the politics of time zones when Venezuelan president Hugo Chavez decided to move his entire country’s time by 30 minutes in a matter of weeks, sending IT technicians spiraling into chaos to accommodate the change on computers and programs.

Time zones can be confusing, but when it comes to figuring out what time it actually is, a little humor never hurt. Posted in the comments on the BBC article by one David Marshall of London, England: “I live in my wife’s time zone, which is 10 minutes later than everyone else’s.”