Timeline of time measurement inventions

From Wikipedia, the free encyclopedia

This timeline of time measurement inventions is a chronological list of particularly important or significant technological inventions relating to timekeeping devices and their inventors, where known.

Note: Dates for inventions are often controversial. Sometimes inventions are invented by several inventors around the same time, or may be invented in an impractical form many years before another inventor improves the invention into a more practical form. Where there is ambiguity, the date of the first known working version of the invention is used here.

Classical antiquity[edit]

  • c. 3500 BC - Egyptian obelisks are among the earliest shadow clocks.[1]
  • c. 1500 BC - The oldest of all known sundials, dating back to the 19th Dynasty.[2]
  • c. 500 BC - A shadow clock is developed similar in shape to a bent T-square.[3]
  • 3rd century BC - Berossos invents the hemispherical sundial.[4]
  • 270 BCE - Ctesibius builds a water clock.

Medieval era[edit]

Modern era[edit]


  1. ^ "Sundial". Encyclopædia Britannica. Retrieved April 4, 2008.
  2. ^ "One of world's oldest sun dial dug up in Kings' Valley, Upper Egypt". ScienceDaily. 14 March 2013. Retrieved 10 May 2021.
  3. ^ Barnett 1999, p. 18.
  4. ^ Dolan 1975, p. 34.
  5. ^ Bergreen 2003, p. 53.
  6. ^ "Ancient Calendars". A Walk Through Time. National Institute of Standards and Technology. 12 August 2009. Retrieved 15 May 2021.
  7. ^ Landes 1985, p. 220.
  8. ^ Marrison 1948, p. 538.