Do you know what a TIME ZONE is? JET LAG? (Learn HERE!)

I wrote this post just after I returned to Japan after a three-week trip to Ontario, Canada. I traveled to Canada to visit my family. The time zone in Ontario is called Eastern Daylight Time. (EDT) Crossing many time zones caused me to be jet-lagged.

This is the perfect time for me to write a post that explains time zones and jet lag for anyone studying English.

What is a Time Zone?

A time zone is a location or area where the same time standard is used. 

Japan has only one time zone. Wherever you are in Japan the time is the same. 6 PM in Tokyo is 6 PM in Okinawa.
Canada has six time zones. This means that in different parts of Canada the time is not the same. 6 PM in Toronto is 3 PM in Vancouver.

I found lots of interesting and useful information about how time zones are made, time zone abbreviations, and the International Date Line. I discovered what jet lag really is, what causes it, and how to get over it quickly the next time you travel. It’s all here!

Why do some countries have more time zones than others? 

Time zones run across the earth from North to South. Japan is a long and narrow island country that runs from North to South so the whole country is in one time zone.

Canada is a very wide country so it crosses many time zones

time zones map wiki

My family in Canada is in a time zone that is 12 or 13 hours earlier than Japan. (If the time is later in Japan then I guess I live in the future!)

How are time zones decided? 

An area’s time zone is decided by a global standard. This is the starting point to calculate all other times. It’s called UTC. (Universal Time Coordinated – also called Coordinated Universal Time or Universal Coordinated Time

Japan is UTC +9 = 9 hours ahead of Coordinated Universal Time 

Ontario, Canada (EDT) is UTC – 5 = 5 hours behind Coordinated Universal Time

Have you ever heard of Greenwich Mean Time? (GMT) I used to think that this was the standard to set the time zones for different areas. Here is what I learned.

What’s the difference between UTC and GMT? 

There’s no difference in their times. 12 p.m. UTC is also 12 p.m. GMT. They are the same time.

Here’s the real difference. UTC is a time standard (measurement) and GMT is a time zone (area). 

standard –  a unit of measurement that is officially used

zone – an area or a region with a particular feature or use

Definitions from Oxford Learner’s Dictionaries

To say that Japan’s time zone is – GMT +9 is the same as saying Japan’s time zone is – UTC +9.

GMT is a time zone that = UTC +/- 0. This means we can use GMT to measure other time zones but… UTC is more commonly used because it is a standard

How many time zones are there in the world? 

How many time zones are there in the world? 

The world is divided into 24 time zones, one zone for each hour of the day. (One day has 24 hours) Many countries have created their own time zones to set some smaller areas apart from others. These smaller time zones can be as little as 30 minutes different from the time zone right beside it. 

France has the most time zones with 12. This includes France’s overseas territories which are located around the world. 

Time Zone abbreviations

Below is a listing of the Time Zone names with their abbreviations. Special thanks to for this list. The gisgeography site is a great teaching resource for anyone who needs to talk about time zones with their own students.

GMTGreenwich Mean TimeGMT
ECTEuropean Central TimeGMT+1:00
EETEastern European TimeGMT+2:00
ART(Arabic) Egypt Standard TimeGMT+2:00
EATEastern African TimeGMT+3:00
METMiddle East TimeGMT+3:30
NETNear East TimeGMT+4:00
PLTPakistan Lahore TimeGMT+5:00
ISTIndia Standard TimeGMT+5:30
BSTBangladesh Standard TimeGMT+6:00
VSTVietnam Standard TimeGMT+7:00
CTTChina Taiwan TimeGMT+8:00
JSTJapan Standard TimeGMT+9:00
ACTAustralia Central TimeGMT+9:30
AETAustralia Eastern TimeGMT+10:00
SSTSolomon Standard TimeGMT+11:00
NSTNew Zealand Standard TimeGMT+12:00
MITMidway Islands TimeGMT-11:00
HSTHawaii Standard TimeGMT-10:00
ASTAlaska Standard TimeGMT-9:00
PSTPacific Standard TimeGMT-8:00
PNTPhoenix Standard TimeGMT-7:00
MSTMountain Standard TimeGMT-7:00
CSTCentral Standard TimeGMT-6:00
ESTEastern Standard TimeGMT-5:00
IETIndiana Eastern Standard TimeGMT-5:00
PRTPuerto Rico and US Virgin Islands TimeGMT-4:00
CNTCanada Newfoundland TimeGMT-3:30
AGTArgentina Standard TimeGMT-3:00
BETBrazil Eastern TimeGMT-3:00
CATCentral African TimeGMT-1:00

Hey, wait a minute! You said there are 24 time zones, this list has 31! That’s true. Here is why there are “extra” time zones.

You will notice that some time zones have two names for the same zone.

EETEastern European TimeGMT+2:00
ART(Arabic) Egypt Standard TimeGMT+2:00
ESTEastern Standard TimeGMT-5:00
IETIndiana Eastern Standard TimeGMT-5:00
AGTArgentina Standard TimeGMT-3:00
BETBrazil Eastern TimeGMT-3:00

They have different names because they are used in different countries. They are still talking about the same zone, it just has a different name.

There are also a few smaller time zones that only have a 30-minute difference. (Not an hour)

METMiddle East TimeGMT+3:30
ISTIndia Standard TimeGMT+5:30
ACTAustralia Central TimeGMT+9:30
CNTCanada Newfoundland TimeGMT-3:30

Russia has 11 time zones all connected on its mainland. This is because Russia is the widest country from East to West in the world! LINK

What is The International Date Line?

The International Date Line is a north-south line in the Pacific Ocean where you turn your calendar back or ahead one day. The center of the time zone roughly follows 180° longitude without crossing any landmass.
The International Date Line Wiki

If you cross the International Date Line going East you need to turn your calendar back one day. If you are going West you need to move your calendar ahead one day. 

When I fly from Japan to Canada I gained one day add when I fly back to Japan I lose a day. 

The first place on Earth to bring in the year 2000 on January 1st was Kiribati. Kiribati is a nation of several islands located near French Polynesia.

The islands of Kiribati


What time zone do you live in? Do you travel? If you fly across several different time zones you may suffer from a condition we call jet lag in English.

What is Jet Lag?

Your body has an “internal clock” and it is set to your normal time zone, just like your watch. This tells you when to sleep (night time) and when to be awake and active (day time). When you travel across several time zones your body has to adjust to night and day because they have shifted several hours.

Jet lag is a temporary sleep problem that can affect anyone who quickly travels across multiple time zones. Mayo Clinic

*Some people may have jobs where they need to work at night so jet lag doesn’t affect them as much as people with a more regular work schedule.

I recently came back from a trip to Canada and I’m suffering from jet lag. The difference between Japan’s time zone and Ontario, Canada’s time zone is 13 hours! This has affected my sleeping pattern.

Jet Lag collocations 

We don’t often say I have jet lag, it is much more common to use it as an adjective and say I am jet-lagged. *We usually write the adjective form with a hyphen (-).

  • I flew back last week but I’m still feeling jet-lagged
  • How was your flight? I hope the food was good, you must be jet-lagged after such a long trip. 

We might also say someone suffers from jet lag or is suffering from jet lag.

  • Is it possible to reschedule tomorrow’s meeting? Three of our staff just came back from a conference in Paris and they’re suffering from jet lag at the moment. 
  • I can’t believe it’s only 4 a.m. I feel wide awake right now. I guess I’m still suffering from jet lag

When our body adjusts to a new time zone after travel our jet lag is gone. We use the phrasal verb get over with the condition jet lag to show we have adjusted. 

  • It took five days but I finally got over my jet lag.
    *We can also BE over jet lag. 
  • It took five days but I’m finally over my jet lag
  • Below you will read about jet lag symptoms find a few tips to help you get over jet lag.

What are Jet Lag Symptoms?

Jet lag affects everyone differently but here are some common symptoms according to National Health Services UK:

  • The main symptoms of jet lag are:
  • difficulty sleeping at bedtime and waking up in the morning
  • tiredness and exhaustion
  • difficulty staying awake during the day
  • poor sleep quality
  • concentration and memory problems 

These problems are not so serious but they can affect the enjoyment of your trip or disrupt your usual routine after returning home. Here are a few tips to help you get over jet lag.

5 Tips for Getting Over Jet Lag

  1. Mentally and physically prepare 

Set your watch to the new time zone before you get on the plane. If it is a long flight the plane will probably serve meals set to match your new time zone. Try to eat at a time that matches the meal time of your destination time zone. (You can easily keep track of this because your watch is already set to your destination’s time!) 

  1. Try to sleep on the plane during the evening time of your destination

It’s a good idea to bring a mask and earplugs on the plane to help block out lights and noise while you’re trying to sleep. (An airplane can be a little noisy.)

  1. Drink a lot of water

Water is your friend! Water is very important for your body to work. If we don’t drink enough water our bodies become dehydrated. (having lost too much water from your body) This will make any jet lag you experience even more difficult. 

  1. Sunlight is also your friend!

Your body naturally reacts to sunlight. It lets your body know it is daytime, a time to be alert and active. This will help you adjust to the new time zone. Get out in the sun if you can!

  1. Do resistance training

This tip is my favorite and I use it every time I travel. Resistance training means working your muscles against the force of gravity. When you lift weights you’re building your muscle by moving heavy objects away from the ground. This is resistant training because you’re moving the weights against the force of gravity.

Here’s the best part, you don’t need weights! My favorite kinds of resistance training are bodyweight exercises like push-ups or bodyweight squats. No gym is required, you can do these exercises anywhere anytime.

Resistance training to fight jet lag.

Try to exercise first thing in the morning rather than later in the evening as the brain chemicals produced by exercise might make you more alert. You want to feel relaxed before bed.

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