Presentation on theme: " All time is measured from Greenwich a suburb of London in England. The zero degree longitude line or the Prime Meridian passes through Greenwich."— Presentation transcript:
All time is measured from Greenwich a suburb of London in England. The zero degree longitude line or the Prime Meridian passes through Greenwich. Greenwich Mean Time (GMT) is the time it is in Greenwich. Greenwich was chosen as a lot of the world’s sea charts were being drawn up in England at that time.
24 hours to make a complete rotation of 360 degrees 360/24=15 Every 15 degrees is approx 1 hour
The earth is divided into time zones. Each time zone has a difference in time of approx 1 hour from Greenwich. Time zones tend to avoid land masses if possible.
The line is at 180 degrees Longitude. Time is on the same on each side of the line, only it is a different day.
The earth travels west to east, hence the west is behind the east. Add 1 hour for each time zone east of Greenwich and subtract 1 hour for each zone west of Greenwich.