Time Zones: Your Ultimate Guide


Time zones are changing all over the world (except for China), and we have British Railways to thank for that.

Time zones are surprisingly complicated. There are only 24 hours in a day, yet there are more than 24 time zones in this world. Managing time zones is a reality of travel – domestic and international. They can disrupt the circadian rhythm during travel and lead to jet lag (although this is also partly the pressurization of the airplane cabin).

People with friends all over the world constantly have to fight with people in different time zones. And this is the bath of setting up international conference calls. To make matters worse, many people don’t even refer to their time zone by its international name – but by its local name. For example, EST of NYC is actually internationally known as UTC -5 (formerly GMT -5). Imagine if everyone did that – so someone in Sydney just said “AEST” not UTC+10 (formerly GMT+10) and hung up the phone.

How Time Zones Were Standardized

In the past, each city had its own time which could be different from each other. When one had to walk from one city to another, it didn’t matter that their time was 10 minutes different from the time recorded in his hometown.

In 1675 the Greenwich Royal Observatory was founded just outside of London and they established Greenwich Mean Time (GMT) – it was just another time kept in England. But everything changed with the advent of the industrial revolution and the development of the railways.

  • GMT: Created in 1675

The railways had to be kept on a constant time and it wouldn’t work if every town had its own time. Eventually the railways started using GMT using portable stopwatches and this became standard and was called Railway Time in Britain.

  • Railways: Scheduled using GMT

In 1855, 98% of Britain’s public clocks used GMT – although it only became legal on August 2, 1880. Before that, there were even clocks with two-minute hands – one for local time and one for GMT time.

Eventually all time zones in the world were based on GMT, all time zones are GMT + or – time increments (normally one hour) based on their longitude. New Zealand adopted GMT in 1868 with GMT+ 11 Hours and 30 Minutes.

Related: 15 DIY Hacks to Overcome Jet Lag Quickly (5 Things That Will Make It Worse)

Time zones divide the world

Today people take it for granted that everyone is compensated in 1 hour increments (or 1 hour splits) – not 6 minute differentials. Today, all time zones are set to GMT.

So while the world has the Royal Observatory and train timetables to thank for a fixed point from which to measure time, time zones are always complicated. There are time zones that sometimes don’t even follow political boundaries. In the United States, counties may be in a different time zone from the rest of the state – such as Indiana counties near Chicago are on Chicago time, not the rest of the state time .

  • Hoover Dam: Two time zones
  • China: Is in one time zone
  • Russia: At eleven time zones

While in the United States a state can be divided into different time zones, China is in one time zone. For them, they seek to emphasize that they are a united country and not divided by time zones. As China is a huge country, the result is that the sun can rise and set at rather odd times in the western part of the country.

While New Zealand is essentially in one time zone, there are a few small offshore islands that are off by 15 minutes for some reason.

Related: 20 essential things to know when booking an international flight

The Strange Case of the International Date Line

The tiny American island of Little Diomede in Alaska’s Bering Strait overlooks the Siberian island of Big Diomede. Between them are 2.5 miles of water and the International Date Line. Basically, the Russian island Big Diomede is always “tomorrow”.

  • Tomorrow: The inhabitants of Little Diomede see tomorrow by looking at the neighboring island

Another oddity is the International Date Line that crosses the Pacific. You can fly on a 14 hour and 20 minute flight from Melbourne, Australia to Los Angeles and manage to wind your clock back 4 hours from the time you boarded the plane! If one lines the place at 6:00 p.m. Wednesday, one flies for 2:30 p.m. and arrives around 2:00 p.m. Wednesday. Of course, going the other way and you lose a day.

Cross the International Date Line:

  • Fly East: win a day
  • Fly west: lose a day

That means it’s perfectly possible to celebrate New Year’s in New Zealand, then hop on a plane, go back to last year in Hawaii, and celebrate it all again. Alternatively, one could simply cross the county line or cross the Hoover Dam to count New Years again.

Next: New app helps you avoid jet lag and adapt to new time zones

25 reasons why Denver’s mysterious airport is unlike any other in the world

About the Author


Comments are closed.