Presentation on theme: "Time Zones Th e world is broken into 24 Standard Time zones. This system was created by a Canadian engineer, Sir Sanford Fleming. Fleming worked for the."— Presentation transcript:
Time Zones Th e world is broken into 24 Standard Time zones. This system was created by a Canadian engineer, Sir Sanford Fleming. Fleming worked for the Canadian Pacific Railway. He realised that there needed to be a system that standardized time so that modern transportation and communications could function efficiently. Prior to Fleming’s system each town and city determined its own local time based on the sun’s position overhead. This meant that every community had a different time. This was particularly odd when looking at towns that were close together, like Newcastle and Bowmanville. Standard time would ensure that each “time zone” shared the same time throughout, without local variation. Fleming determined that each time zone would be approximately 15° and that there would be 24, one for each hour of the day. Standard time would allow for easier scheduling of trains and for much easier communications via telegraph and telephone as well as radio.
Fleming chose the Prime Meridian, 0° longitude, to be the base point for his Standard Time Zones. Each 15° of longitude to the west results in the clock being set back 1 hour and for each 15° to the east the clocks go ahead 1 hour. The time zones meet at the 180° line of longitude, the International Date Line. Sometimes time zones do not follow the exact line of longitude, varying to either side to accommodate national or physical boundaries or local communities. There are some places which fall into the middle of a time zone and those, usually islands, chose to alter their time by a ½ hour instead of a full hour. Daylight Savings Time was created to provide more daylight hours so that farmers could harvest later into the evening. While no more sunshine is created, the change in time moves the sunshine to more useable hours for northern latitudes. In the spring time “springs forward” and then “falls back” in the autumn. This hour shift provides better timing for farmers and it also allows for conservation of energy through using fewer lights in the evening.