2In this Lesson… You will learn the origins of time zones. You will understand how time zones workYou will learn about Canada’s time zones.You will know the purpose of daylight savings time.You will be able to explain the tools explorers used to determine location.
3Imagine a World Without Time Zones! It would be quite chaotic! What are some problems that would occur?
4Time Zones Background The world is divided into 24 time zones. The world turns 360° in one day, so each time zone is 15° wide (360/24)The International Date Line (IDL) at 180° is the designated line for date change.If it’s Sunday in Alaska, it’s Monday in Siberia.
5World Time Zone Map Each time zone = 15° wide Time zones run along lines of longitude, so each place along that line will be in the same time zone.Greenwich Mean Time
6I invented time zones for railway time schedules. Sir Stanford FlemingChief surveyor for the Canadian Pacific Railway…a Canadian!Needed standard times for trains to run on schedule.Idea for 24-one-hour time zones was accepted at the International Prime Meridian Conference in 1884.This is the global standard we use today.I invented time zones for railway time schedules.
7Canadian Time Zones Canada has 6 time zones. BC is located in Pacific Mountain TimeToronto is 3 hours ahead of us.Creston is one hour ahead of us only in the spring during Daylight Saving Time.Nfld has it’s own 1/2 hour time zone.Click here for more info.
8Click on icon for activity. Canada Time Zone MapClick on icon for activity.
9Daylight Saving TimeDST was proposed by an American named Benjamin Franklin.He thought it would save energy costs during the day.It would also extend the summer days by an hour so people could enjoy staying out.“Spring forward, fall back” 1st Sunday in April, last Sunday in October.Click here for more info
10Greenwich Mean TimeYou can tell what time it is in your area by knowing:Greenwich Mean TimeYour longitudeEg./What is your time if you’re 105°E of the Prime Meridian and GMT is 4:00 pm?Answer: 105 divided by 15=7.If it’s 4 pm GMT, then add 7 hours. So, it’s 11 pm where you are. In which continent are you?
11How Explorers Navigated Early explorers used latitude to chart their course.They used a sextant to determine latitude by measuring the angle of the North Star from the equator.In the South, they used the Southern Cross star in a similar way.astrolabesextant Click here for more info.
12How Explorers Found Longitude They would need a chronometer that told the GMT (Greenwich Mean Time).They would use a sundial to tell them the ship’s time.They would calculate their longitude based on the difference between GMT and their time x 15°.sundialchronometercompass
13Navigating With Giovanni According to our sextant, we are sailing at 20°N. If it is 10 am according to our sundial, and GMT is 4 pm, where are we?Answer: There is six hours earlier difference. Multiply 6 x 15° = 90°W.Can you figure out where we are?Click on icon for answer.
14Other Links of Interest to Try Anchors Aweigh! GameDaylight Saving Time websiteWatch the GMT Clock TickingTime in Other Cities Around the World