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Time Zones.

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Presentation on theme: "Time Zones."— Presentation transcript:

1 Time Zones

2 What are Time Zones? There are 24 hours in a day, and there are 360 degrees of longitude around the Earth, so math tells us that there should be exactly 24 time zones, each one exactly 15 degrees wide (but that is not the case, we will see why)

3 How Many Are There? If each time zone were 1 hour apart, there would be 24 in the world. However, several time zones are only 30 or 45 minutes apart (fractional time zones), so there are actually 30 time zones! Offset from UTC Location Newfoundland Time Iran Afghanistan India Burma Mid Australia

4 How Are They Measured? The time within a time zone is defined by its distance away from the Prime Meridian, or Coordinated Universal Time (UTC), the world's time standard. UTC time changes 1 hour forward and backward for every 15 degrees east or west of the prime meridian (0° longitude)

5 Time Zone Names Each time zone can have different local time zone names For instance in Miami, Florida, is 5 hours behind UTC (UTC-5) and it is in the Eastern Standard Time zone (EST). In Havana, Cuba, the standard time zone is also UTC-5, but it's called Cuba Standard Time (CST).

6 What did people do before time zones?
Historically, many towns and cities set their clocks based on sunsets and sunrises. Time differences between distant locations were barely noticeable before the 1800s because of long travel times and the (lack of) long-distance communications. American railroads maintained many different time zones during the late 1800s. Each train station set its own clock making it difficult to coordinate train schedules and confusing passengers. Canadian Sir Sanford Fleming developed the system of standard time.

7 Time Zones in Canada We have 6 time zones in Canada (Russia has 11!)
All of them are the standard 1 hour difference, except for Newfoundland, who is only a half hour different

8 Time Zones in Canada

9 Watch the Earth rotate

10 What is Daylight Saving Time?
This year Daylight Saving Time began at 3:00 AM on Sunday, March 12 and will end at 2:00 AM on Sunday, November 5 Daylight Saving Time or “DST” is a way of making better use of the daylight by setting the clocks forward one hour during the summer months, and back again in the fall. The clock moves ahead (= losing one hour) in the spring when DST starts, and falls back one hour (= gaining one hour) when DST ends in the fall. To remember which way the clock goes, keep in mind one of these sayings: “spring forward, fall back” or “spring ahead, fall behind.”

11 Daylight Saving Time = Not Universal

12 Daylight Saving Time 637iYhDE 2:02 “Daylight Savings Time Explained” W9ufUUw “How is this still a thing?” 3:16

13 World Time Zones * Adjusted for DST, except for Beijing and Hawaii)
Vancouver: Fri, 10:30 am England: Fri, 6:30 pm Toronto: Fri, 1:30 pm China: Sat,1:30 am Israel: Fri, 8:30 pm Hawaii: Fri, 7:30 am Sydney: Sat, 4:30 am Fiji: Sat, 5:30 am

14 https://www. youtube. com/watch
QqcmCfm8 Strangest Time Zones in the World, 8:38 DfqqHsI Should we just have a single, world-wide time zone? 1:09


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