Add to table of contents: Time zone questionsPg. 10 Time ZonesPg. 11

Time Zones Pg 11 The Prime Meridian-is the meridian with a longitude of 0°. It is a basis for standardized time zones. There are 24 time zones.

It was adopted officially in 1884 as a line from which longitude east and west are measured..It passes through Greenwich, England, home of the Royal Greenwich Observatory. The Observatory was founded in 1675 and closed except as a museum in The prime meridian, together with its opposite meridian(the International Date Line at 180°) divide the Earth into the Eastern and Western Hemispheres.

The International Date Line-is the imaginary line on the Earth that separates two consecutive calendar days. -it is at 180°

The date in the Eastern hemisphere, to the left of the line, is always one day ahead of the date in the Western hemisphere. Without the International Date Line travelers going westward would discover that when they returned home, one day more than they thought had passed, even though they had kept careful tally of the days. Likewise, a person traveling eastward would find that one fewer days had elapsed than he had recorded.

The International Date Line can be anywhere on the globe. But it is most convenient to be 180° away from the Prime Meridian that goes through Greenwich, England. It also is fortunate that this area is covered, mainly, by empty ocean. However, there have always been zigs and zags in it to allow for local circumstances.

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US Time Zones-Pacific -Mountain -Central -Eastern (Alaska Standard Time) (Hawaii-Aleutian Standard Time)

If it is 7am in Las Vegas, what time is it in New York City? _____________________ If it is 1pm in most of Texas, what time is it in Calif?_

1. Complete the Time zone question page and turn in. 2. Work on the review sheet over our first unit- safety/observations/mapping. 3. Test next class. Notebook is due! Don’t “forget” it!