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CONTENTS
TIME DIFFERENCES JET LAG/ JET FATIGUE
ACROSS THE WORLD CALCULATIONS…………
………………………………………
TIME ZONES VOCABULARY . PRACTICAL APPLICATION
ADDING FLYING TIME
INTRODUCTION: THE
WORLD TIME ZONE MAP/ DAYLIGHT SAVING TIME
INFLATABLE BALLS
…………………………………………………………………………………………………………………………………………………………………………………………………………………………………

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 1. TIME DIFFERENCES ACROSS THE WORLD

A time zone is a region of the

earth that has adopted the
same standard time; which is
usually referred to as the
local time.

Time zones are indicated as

imaginary lines that run from
North to South down the
globe.
Time zones are not straight
lines – they curve or form
angles so that they go around
some smaller countries to
ensure that the entire has the
same time zone.
Example: some lines curve
around the Pacific Island
groups so that island
countries that cover relatively
smaller areas will not have
different time zones.
As the earth rotates on its
axis (from west to east), half
of the planet experiences
day, and the other half
experiences night. It is
therefore understandable that
all places on earth cannot
have the same time.

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2. TIME ZONE VOCABULARY

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 3. INTRODUCTION TO WORLD TIME ZONE MAP

ALL PLACES WEST OF UTC WILL BE ALL PLACES EAST OF UTC WILL BE

EARLIER (subtract time) LATER (add time)

            +1 +2 +3 +4 +5 +6 + + + + + +
12 11 10 9 8 7 6 5 4 3 2 1 7 8 9 10 11 12
UTC

18 165˚ 150˚ 135˚ 120˚ 105˚ 90˚ 75˚ 60˚ 45˚ 30˚ 15˚W 15˚ 30˚ 45˚ 60˚ 75˚ 90˚ 105˚ 120˚ 135˚ 150˚ 165˚ 180˚
0˚ W W W W W W W W W W E E E E E E E E E E E E

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3.1 Important lines of the World Time Zone Map:

3.1.1 Time Zones

There are 24 time zone lines drawn from the South to the North pole. Each represents 15 degrees longitude, or the
distance that the earth rotates in one hour.

3.1.2 The Universal Time Coordinate

Time zones maps were based on Greenwich Mean time (GMT, also known as UT1), 0° line of longitude (the Prime
Meridian). However, the Coordinated Universal Time (UTC) because of its accuracy. Most nations use the UTC in
the definition of their time zones.

Example: South Africa used UTC +2, instead of GMT +2

As one travels West from the UTC, the time becomes earlier; as one travels east, the time becomes later.
To indicate time ahead of the UTC, + is used AND To indicate time behind UTC, - is used

Example: a country 30°E, will be UTC +2 AND a country 30°W, will be UTC -2

The hours a country is ahead of or behind UTC is called the standard time (local time) for that specific country

3.1.3 International Date Line (IDL)

The International date Line is at 180° longitude.
The date is either different on either side of this imaginary line located in the Pacific Ocean.
The date is altered at 12:00 or 180° from the Greenwich. This line runs smoothly through the open Pacific Ocean –
however, the IDL makes a zigzag in the to incorporate a number of islands into onetime system.

A traveller going Eastwards across the Date Line from one Island to another would have to reset her watch
because although she would still be in the same time zone, on arrival at the other island she may find that the
time is the PREVIOUS DAY!

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 4. CALCULATIONS
4.1 The 2-hour Clock

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4.2 Calculation Methods

4.2.1 Illustrative Example:

4.2.1 Calculating the time and day in different
time zones If the time is 09:00 in South Africa. Determine
the time and day in New York
GENERAL DIRECT QUESTION:
Solution:
Step 1: Identify the time zones of the countries
in question. Step 1:
Step 2: Determine the time difference between Use the time zone map to identify the time
the two countries. zones:
Step 3: Determine the direction of travel to see South Africa: UTC+2 and New York: UTC-5
if you should add the time difference or
subtract the time difference, to Step 2:
determine actual time *Use the time zone map: Put a finger on the Time
 Always start from the known country (SA) to the zone for SA (+2) and move until you reach the
unknown time zone for New York (-5), as your finger move
 If you move forward / to the right/east from
you count the number of time zones that you
known to unknown, you will
ADD the time difference. cross. OR *Draw a number line to represent all
 If you move backward / to left/west from known the time zones and count the SPACES BETWEEN
to unknown, you will the two timelines from one country to the next.
SUBTRACT the time difference
-6 -5 -4 -3 -2 -1 0 +1 +2 +3 +4

SOLUTION Step 3: If you move from SA (known) to New York

South Africa = +2 (unknown), you are travelling backwards/ to
New York =-5 the left therefore you will subtract the time.
Time difference = 7 hours
(known time – time difference = actual time) * On Time zone Map: finger on +2 and move
09:00 – 7hrs = 02:00 to -5 , at every time zone that you cross you
It will be 02:00 on the same day subtract one hour. OR * On 24 hr clock: Start
at known time and move backwards while
counting 7 hrs OR * Mathematically: Subtract
7
7 from 9 to determine actual time.
 5. FLYING TIME
Tourists often travel between countries/cities situated in different time zones. Therefore, it is important for a tourist to
be able to determine what his arrival time will be in the country. Flying time refers to the approximate time that has
elapsed since his/ her departure.

If you want to determine the arrival time you must ADD the flying time to the answer obtained after step 3.
If you want to determine the departure time you must SUBTRACT from the answer obtained after step 3

Illustrative Example
Mr. Ace Khumalo from South Africa will be departing on a business trip to Rio de Janeiro on 21 March 2019 at 08:00 and
his flight will last for fourteen hours. What will the time and date be when he arrives in Rio De Janeiro?

Instruction 1: Complete steps 1 – 3

South Africa = +2
Rio de Janeiro = - 3
Time difference = 5hrs
08:00 – 5hrs = 03:00
Instruction 2: Add the flying time
03:00 + 14 hrs flying time = 17:00 on 21 March 2019

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 6. Daylight Savings Time (DST)

Daylight Savings Time (DST) is the practice of moving clocks ahead usually, but not always, by one hour. Daylight saving
time is most often implemented in the spring and ends in late autumn. DST is also known as summer time in some
locations.
The benefit of daylight-saving time is that by moving the clock ahead by one hour, sunset will happen later in the day
thus creating more daylight for people to take advantage of. By having more daylight later in the day the theory is that
less energy will be used for lighting, more people will go shopping after work because it is still daylight, people will
have more recreation time later into the night and so on.
When daylight saving time ends and the clocks are moved back to the original time, the time is then referred to as
Standard Time

6.1 Application of DST in time zone calculations:

Determine which countries are using DST. Take note of any dates in the question.
Countries only apply DST in summer.
DST makes a difference of 1 hour to the actual time. It will be ONE hour later.
ADD the one-hour DST to the time zone for countries to the EAST and SUBTRACT an hour for the
……………………countries to the WEST. ALTERNATIVELY : ADD/ SUBTRACT the 1 hour for DST at the end of your
……………………calculations
If both countries use DST at the same time, it will have no effect on the answer

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EXAMPLE
It is Friday 04 July in New York. An exchange student living in Durban would like to call his parents at home in New York at 17:00
SAST. What will the time be in New York when he calls?

South Africa = +2
New York = -5
Time difference 7hours
17:00 – 7hrs = 10:00 + 1hr (DST) = 11:00 the same day/ Friday 04 July

7. JET LAG / JET FATIGUE

7.1 Definition: Jet lag is a general feeling of fatigue and disorientation often experienced by travellers who cross several time
zones in relatively few hours.

7.2 Causes:
Pre-flight condition over-tired, excited, stressed, nervous, or you drank too much before the flight
Dry atmosphere -
Cabin pressure –
Stale air -
Alcohol -
Food and drink -
Lack of exercise –

7.3 Symptoms:
Sleeplessness / insomnia; excessive daytime sleepiness; fatigue; headaches; indigestion; irritability; lack of concentration;
deep vein thrombosis

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7.4 How to minimise the effects of jet lag
Before the flight During the flight After the flight
Ensure that you are in good Do not drink alcoholic or Try and get at least one hour
physical shape caffeinated beverages of sunlight after reaching the
Eat healthy Drink plenty of water to destination, if travelling
Rest or get enough sleep offset the effects of the dry WEST
before departure air in the plane Adapt clock/ watch to the
Get up earlier prior to an Do not eat too much on the local schedule to help the
EAST trip plane. body adapt faster
Walk around in the cabin Adjust sleeping patterns
every hour or two according time at the
No sleeping pills destination without resorting
Catch a connecting flight to to sleeping tablets.
allow stayovers in the city
Wear comfortable clothes
and shoes

8. PRACTICAL APPLICATION
8.1 Determine the time in the following cities if it is 12:00 in JOHANNESBURG. Do not consider DST.

a) New York
b) Perth
c) Cairo
d) Los Angeles
e) Paris
f) Rio de Janeiro
g) London
h) Beijing

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8.2 Determine the day, date and time in South Africa if it is: (do not consider DST)

TIME CITY DAY DATE

07:00 Alaska Wednesday 13 August
06:00 Moscow Saturday 10 May
17:00 Dallas Monday 1 November
24:00 Tokyo Sunday 26 December
04:00 Sydney Thursday 22 February
18:00 Rio de Janeiro Friday 3 July

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8.3 PREVIOUS GRADE 12 QUESTIONS:

SAMPLE 1: STUDY THE WORLD TIME ZONE MAP AND ANSWER THE QUESTIONS THAT FOLLOW:

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SAMPLE 2:
2.2 STUDY THE WORLD TIME ZONE MAP AND ANSWER THE QUESTIONS THAT FOLLOW:

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ANSWERS AND SOLUTIONS:

9.1
CITY TIME ZONE Time Earlier Or Time in that
Later City
(a) New York -5 7 h earlier 05:00
(b) Perth +8 6 h later 18:00
(c) Cairo +2 0 12:00
(d) Los Angeles -8 10 h earlier 02:00
(e) Paris +1 1h earlier 11:00
(f) Rio de Janeiro -3 5 h earlier 07:00
(g) London 0 2 h earlier 10:00
(h) Beijing +8 6 h later 18:00

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9.2

TIME CITY TIME IN SA DAY DATE

07:00 Alaska 18:00 Wednesday 13 August

06:00 Moscow 05:00 Saturday 10 May

17:00 Dallas 01:00 Tuesday 2 November

24:00 Tokyo 17:00 Sunday 26 December

04:00 Sydney 20:00 Wednesday 21 February

18:00 Rio de Janeiro 23:00 Friday 3 July

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9.3 PREVIOUS QUESTION PAPERS

SAMPLE 1:

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SAMPLE 2:

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