How People Have Told Time

By kjcarpenter
  • 2100 BCE

    12 Hour Clock System

    Early Egyptians divided the day (dawn to dusk & dusk to dawn)
  • 2000 BCE

    24 Hour Clock System

    originated with the ancient Babylonians (numeric system based upon the number 60)
  • 700 BCE

    Early Romans 12 Hour Clock

    Early Romans also used a 12 hour clock that divided day and night into 12 equal hours
  • Jan 1, 1400

    O'clock

    The term "o'clock" was adopted by many people (ex: let's meet at 7 o'clock)
  • Jan 1, 1500

    a.m and p.m

    " a.m" and "p.m" used as a faster and simpler way to indicating daytime or nightime

  • Mechanical Clocks

    introduced in the 1600's - knowing time accurately was possible and became an expectation

  • 24 Hour Clock System

    many countries in the world started using the 24 hour system

  • Present Day Time Keeping

    Present time keeping is a mixture of 24 hour clock and 12 hour clock. This depends on the choice of the country, but many activities (travel, military, computers, businesses, factories) universally use the 24 hour system.