The Timeline of the Telling Time By tmaggie 5000 BCE Early humans use circadian rhythm 3000 BCE Egyptians use the obelisk to tell time. 3000 BCE Early Greeks and Egyptians design a water clock. 300 BCE Babylonians use the sundial to tell time. 1100 The hourglass used in Europe 1300 Mechanical clocks representing a 12-hour period in Europe. 1400 Watches or timepieces portable time. Appeared first in Italy. 1500 Nicolas Copernicus' philosophy that sun revolves around sun annually and every 24 hours on its own axis