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High-Tech Channel Hitachi High-Tech GLOBAL

Rational or irrational? The life cycles of people of the past

Base data: time.
This unit divided time spanning from just before sunrise to just after sunset into six equal lengths.

Length of daytime differs between summer and winter

People of the past used to divide time into six equal lengths spanning from “ake-mutsu (dawn)” to “kure-mutsu (dusk)”. The length of time differs between summer and winter, so this may seem irrational at a glance, but the time could largely be understood by the position of the sun, so it was actually useful for everyday life.