AIM: What are time zones and why are they important? Lesson #6 AIM: What are time zones and why are they important? Do Now: Why do you think East Coast football games start at 1:00 and West Coast games start at 4:00?

The Shape of the Earth The Earth is shaped like a ball or a sphere. To go completely around the Earth, you must travel 360o. The Sun only shines on half the planet at a time. The line the divides the Earth into day and night is called the Terminator. But because the Earth spins or rotates is a counter clockwise or West to East direction, sunlight will touch all of the Earth in a 24-hour period.

The Shape of the Earth (cont.) The position of the Sun changes in the sky throughout the day and is different depending where you are on the planet. Example: In the morning, the Sun is rising in Brooklyn, but setting in Tokyo, Japan.

Time Zones Time on Earth is divided into 24 hours. The Earth is also divided into 24 sections that run north to south called Time Zone. Each Time Zone equals a 15o slice of the Earth from North to South. 15o x 24 = 360o

Facts about Time Zones There are 24 time zones. Time Zones start at the Prime Meridian (0 degree longitude) Time is said to start at the of Greenwich, England.(where the Prime Meridian crosses) Because Time Zones cross each other at the North and South poles, the distance between them varies depending on how North or South you are. Time Zones are not always straight (north and South). Sometime the Time Zone is zigzagged to include territories in the same Time Zone. The International Date Line (180 degrees longitude) divides the days of time. Example Monday and Tuesday.

Time Zones in the United States The US has 6 time zones 4 on the US mainland Eastern Central Mountain Pacific 1 for Alaska 1 For Hawaii

How do we use Time Zones 14 -12 8 2 +6 14 You can calculate the time of any city if you know the time in 1 Time Zone and the number of Time Zones you need to cross to get to the city you wish to know the time. Example 1: It is 8:00 a.m. in Brooklyn, what time is it in Paris. 14 -12 2 It’s 2p.m. 8 +6 14 It’s more than 12 so….. Paris Brooklyn

Going East – the day gets later. Going West – the day gets earlier How do we use Time Zones Example: It is 8:00 a.m. in Brooklyn, what time is it in L. A. 8 4 It’s less than 12 so….. It’s 4 a.m. LA Brooklyn Going East – the day gets later. Going West – the day gets earlier

Important Remember- The Earth’s day is divided into 2 12 hour periods (the morning and afternoon) Morning time is designated by a.m. and afternoon is designated by p.m. When determining a time for a city on a test, make sure you change the a.m. and p.m. if you cross over 12:00. This happens if you count later or earlier. Example: If you start at 10 a.m. and count 4 time zones; it is not 14 o’clock, it is 2 p.m. You must change the a.m. to p.m. because you crossed 12:00

Times of other Cities in Respect to your City. Depending of the location of other cities when compared to your location, some cities can have times that are ahead of you, behind you or the same time as you. If the city is located East of your city and in a different time zone, the city is later in the day than your city. Example – NYC is 12 p.m. and Rome is 6 p.m. If the city is located West of your city and in a different time zone, the city is earlier in the day than your city. Example – NYC is 12 p.m. and LA is 8 a.m. If the city is located North or South of your city and is in the same time zone, the city has the same time as your city. Example – NYC is 12 p.m. and Boston is 12 p.m. and Miami is 12 p.m.