Telling Time in Tokugawa Japan: Physics Today

“In 17th-century Japan, Western clocks seemed nonsensical to consumers because they measured time in 24 equal hours and were dissociated from natural events like dawn and dusk. By contrast, the Japanese people divided their day into 12 unequal hours, following an ancient Chinese system introduced in Japan in the 7th century.”

Read the Article | Physics Today | Sara J. Schechner

“A Japanese-made clockwatch of the 18th century, or Wadokei. Then time changed in the season because from sunrise to sunset made 12 hours and from sunset to sunrise made 12 hours.” Musée Paul-Dupuy, CC BY-SA 4.0 , via Wikimedia Commons