Time Zones Subtitle

Day and Night Rotation: is one complete turn around the Earth’s axis Rotation causes day and night

Rotation The earth rotates at a speed of 1000 miles per hour It rotates from west to east Earth's rotational axis points in the same direction relative to the stars, so that the North Pole points towards the star Polaris

What is a time zone? Areas sharing the same time Why do we have time zones? Areas sharing the same time There are 24 time zones in the world (same number of hours in a day) We have time zones so that appropriate times correspond with daylight and night For example, if we only had 1 time zone in the world it would be dark during the day hours for half of the world https://www.timeanddate.com/time /map/

Universal Time Greenwich Mean Time Coordinated Universal Time Greenwich Mean Time: originally used as the international civil time standard The basis for civil time used today Developed in 1967 Last modifications were made in 1972, when scientists accounted for leap seconds

Greenwich Time Zone

Time Zones in the United States Alaskan Time Zone Hawaiian Time Zone Mountain Time Zone Pacific Time Zone Central Time Zone Eastern Time Zone