HOW TIDE CLOCKS WORK Tide Clocks are clocks that tell the tide. They show you how many hours there are until Low Tide or High Tide. They have a quartz movement that is set to the time it takes the moon to rotate around the earth. The moon is the major cause of the tides. The lunar day, the time it takes for the moon to reappear at the same place in the sky, is 24 hours and 50 minutes. Most locations in Australia and around the world have 2 high...