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Time ZonesTime ZonesStage 6 - Year 12Stage 6 - Year 12

General MathematicsHSC

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Time Zone (1/9)

Map

Time zones are calculated in relation to GMT.Greenwich Mean Time

For locations to our east we add time.

SydneyAdelaide9am

Sydney =Adelaide + 30min= 9am + 30min= 9:30 am

9:30am

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Time Zone (1/9)

Map

Time zones are calculated in relation to GMT.Greenwich Mean Time

For locations to our east we add time.

For locations to our west we subtract time.

PerthAdelaide

9am

Perth =Adelaide – 1hr 30min= 9am - 1hr 30min= 7:30 am

7:30am

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Time Zone (2/9)

Map

If it is 7:08am [07:08 hrs]

hours in London …

… what time isit in Sydney?

Sydney =London + 10hr [East]= 07:08 + 10hr= 17:08= 5:08 pm

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Time Zone (3/9)

Map

If it is 10:20am [10:20 hrs]

hours in Sydney …

… what time isit in Honolulu?

Honolulu =Sydney - 20hr [West]= 10:20 - 20hr= -10:20+ 24:00= 14:20 yesterday

= 2:20 pm yesterday

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Time Zone (4/9)

Map

If it is 10:20am [10:20 hrs]

hours in Sydney …

… what time isit in Honolulu?

Honolulu =Sydney + hr [East]= 10:20 + 4 hr [Crossing ‘Date Line’

subtract one day]= 14:20= 2:20 pm yesterday

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Time Zone (5/9)

Map

When crossing the International Date Line…

•going east – subtract one day

•going west – add one day

When determining time zones

1o in longitude equals 4 minutes.

15o in longitude equals 1 hour.

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USA Time Zones (6/9)

Map

75oWTime Zone

= -75 x 4 mins= -300 mins= -5 hrs

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USA Time Zones (7/9)

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75oWTime Zone

= -90 x 4 mins= -360 mins= -6 hrs

-590oW

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USA Time Zones (8/9)

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75oWTime Zone

= -105 x 4 min= -420 mins= -7 hrs

-590oW

-6105oW

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USA Time Zones (9/9)

Map

75oWTime Zone

= -120 x 4 min= -480 mins= -8 hrs

-590oW

-6105oW-7

120oW-8