Presentation on theme: "Time Zones Lesson Socials 8 Mr. Goldsack In this Lesson… You will learn the origins of time zones. You will understand how time zones work You will learn."— Presentation transcript:
In this Lesson… You will learn the origins of time zones. You will understand how time zones work You 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.
Imagine a World Without Time Zones! It would be quite chaotic! What are some problems that would occur?
Time 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.
World Time Zone Map Time zones run along lines of longitude, so each place along that line will be in the same time zone. Greenwich Mean Time Each time zone = 15° wide
Sir Stanford Fleming Chief 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.
Canadian Time Zones Canada has 6 time zones. BC is located in Pacific Mountain Time Toronto 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. Click here for more info.
Canada Time Zone Map Click on icon for activity.
Daylight Saving Time DST 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” 1 st Sunday in April, last Sunday in October. Click here for more info
Greenwich Mean Time You can tell what time it is in your area by knowing: a) Greenwich Mean Time b) Your longitude Eg./ 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?
How 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. Click here for more info.Click here for more info. sextant astrolabe
How 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°. compass sundial chronometer
Navigating 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.
Other Links of Interest to Try Anchors Aweigh! Game Daylight Saving Time website Watch the GMT Clock Ticking Time in Other Cities Around the World