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3000 BCE
Obelisks
Egyptians use an obelisk and the shadow cast by the sun as a shadow clock. -
500 BCE
Water Clocks
Greeks and Egyptians designed a water clock for telling the amount of time that had passed. -
300 BCE
Sundials
People in Babylonia start using a sundial with a 12-hour clock face and the sun to tell time. -
520
Time Candles
The Chinese use "time candles" to tell time based on how much of the wick had burned. -
1100
Hourglass
Use the hourglass began in Europe with 2 upright containers connected by a small neck. Sand (or other material) flowed from the top to the bottom. -
Period: 1300 to
Mechanical to Analog Clocks
The rise of mechanical clocks began in Europe began with the introduction of weights and balances to mark out increments of time in a 12-hour period. Pendulums were added later and increased a clock's accuracy, also allowing the precision of minutes and seconds. -
International Date Line
Located 180 degrees from the prime meridian, the International Dateline delineates the the move forward or backward of a 24-hour period. -
Greenwich Mean Time
Standard time zones made it possible to record time in a consistent and predictable manner. -
Daylight Savings Time
Some countries, notably Canada, the U.S., and France use the idea of daylight saving and move their clocks an hour forward in the fall and an hour back in the spring in order to maximize the amount of usable daylight. -
Period: to
Digital Clocks
Modern clocks and watches use a quart crystal and batteries to keep accurate time. -
Universal Time Coordinate
A highly accurate system still using GMT was adopted around the world as the official measure of time for the planet.