TimezonesTimezones

CGC1DCGC1D

Time ZonesTime Zones The Earth has 24 times zonesThe Earth has 24 times zones because it takes because it takes

the Earth 24 hours to revolve around its axisthe Earth 24 hours to revolve around its axis Most time zones are one hour apartMost time zones are one hour apart Since the Since the EEarth rotates 15 degrees of arth rotates 15 degrees of

longitude per hour, the longitude per hour, the EEarth’s 360 degrees arth’s 360 degrees were divided into 24 zones, each measuring were divided into 24 zones, each measuring about 15 degrees in width (about 15 degrees in width (360360 / 24 = 15 / 24 = 15))

Every place within a time zone has the same Every place within a time zone has the same time, referred to as its standard timetime, referred to as its standard time

History of TimezonesHistory of Timezones

Standard time zones were not Standard time zones were not required prior to the 1800s because required prior to the 1800s because it was impossible for people to travel it was impossible for people to travel large distances in a short period of large distances in a short period of timetime

The development of rapid railway The development of rapid railway transportation changed travel transportation changed travel dramatically, allowing people to dramatically, allowing people to travel large distances quicklytravel large distances quickly

History of TimezonesHistory of Timezones

This caused confusion, since every This caused confusion, since every town set their own clocks by the suntown set their own clocks by the sun• Ex: 8:00 in Ottawa would be about 7:45 Ex: 8:00 in Ottawa would be about 7:45

in Torontoin Toronto A Canadian engineer same Sir A Canadian engineer same Sir

Sandford Fleming proposed a system Sandford Fleming proposed a system of standard time zonesof standard time zones

Global Time ZonesGlobal Time Zones The prime meridian is the centre time The prime meridian is the centre time

zonezone Time in this zone is called universal Time in this zone is called universal

time (UT) and the standard time in time (UT) and the standard time in other zones is compared to itother zones is compared to it

Time zones Time zones west west of the prime of the prime meridian are earlier than the meridian are earlier than the universal time (the time at the prime universal time (the time at the prime meridian)meridian)

E.g. if UT is 12:00am, next time zone E.g. if UT is 12:00am, next time zone west is 11:00pm.west is 11:00pm.

Global Time ZonesGlobal Time Zones

Time zones Time zones easteast of the prime of the prime meridian are later than the universal meridian are later than the universal time (the time at the prime meridian)time (the time at the prime meridian)

E.g. if UT is 12:00am, next time zone E.g. if UT is 12:00am, next time zone east is 1:00am.east is 1:00am.

Canada’s TimezonesCanada’s Timezones

Canada spans 6 time zonesCanada spans 6 time zones From east to west they are:From east to west they are:

Newfoundland Time ZoneNewfoundland Time Zone

Atlantic Time ZoneAtlantic Time Zone

Eastern Time ZoneEastern Time Zone

Central Time ZoneCentral Time Zone

Mountain Time ZoneMountain Time Zone

Pacific Time ZonePacific Time Zone

Ottawa’s TimezoneOttawa’s Timezone

Ottawa is in the Eastern Ottawa is in the Eastern Standard Time ZoneStandard Time Zone• If it is 1:00pm in Ottawa it is the same in If it is 1:00pm in Ottawa it is the same in

all of this time zoneall of this time zone

If I could travel around the earth (to the east) in an instant I would cross 24 time zones. Each time I would cross a time zone I would move my clock up one hour. When I get back to where I started I would be one DAY ahead of everyone else!

This happened to a famous explorer by the name of Ferdinand Magellan. In order to correct this problem The International Dateline was created.

It is an imaginary line that simply tells travelers to adjust their calendars. If you are traveling east and cross the dateline you go back one day. The dateline is the 180 degree line of longitude, directly opposite the Prime Meridian.

The International Dateline

Monday Sunday

Daylight Savings TimeDaylight Savings Time

Many parts of the world change their Many parts of the world change their time according to the seasontime according to the season

During the summer, daylight saving During the summer, daylight saving time is used to extend daylight time is used to extend daylight hourshours

For example the sun in standard time For example the sun in standard time would set at 8:00pm but when time is in would set at 8:00pm but when time is in daylight savings it would set at 9:00pm daylight savings it would set at 9:00pm (therefore 1 more hour of daylight)(therefore 1 more hour of daylight)

Daylight Savings TimeDaylight Savings Time

Energy is saved and people get Energy is saved and people get to enjoy more of the dayto enjoy more of the day• i.e. wake up when light, go to bed when i.e. wake up when light, go to bed when

darkdark In Canada time is changed to In Canada time is changed to

daylight saving on the second daylight saving on the second Sunday in March and ends the first Sunday in March and ends the first Sunday of NovemberSunday of November

““Spring ahead, fall back”Spring ahead, fall back”

Observe Daylight Savings Time Tried it but gave it up

Never used it

What’s up with Saskatchewan?What’s up with Saskatchewan?

Saskatchewan is naturally located within Saskatchewan is naturally located within the Mountain Standard Time (MST) – the the Mountain Standard Time (MST) – the same timezone as Alberta.same timezone as Alberta.

Under The Time Act of 1966, Saskatchewan Under The Time Act of 1966, Saskatchewan adopted Central Standard Time, so shares adopted Central Standard Time, so shares the same timezone as Manitobathe same timezone as Manitoba

But since they don’t observe Daylight But since they don’t observe Daylight Savings time, they share the same time as Savings time, they share the same time as Alberta during the summer months and the Alberta during the summer months and the same time as Manitoba during the winter same time as Manitoba during the winter monthsmonths