Japanese Clock - Temporal Hours

Temporal Hours

Adapting the European clock designs to the needs of Japanese traditional timekeeping presented a challenge to Japanese clockmakers. Japanese traditional timekeeping practices required the use of unequal temporal hours: six daytime units from local sunrise to local sunset, and six night time units from sunset to sunrise.

As such, Japanese timekeepers varied with the seasons; the daylight hours were longer in summer and shorter in winter, with the opposite at night. European mechanical clocks were, by contrast, set up to tell equal hours that did not vary with the seasons.

Most Japanese clocks were driven by weights. However, the Japanese were also aware of, and occasionally made, clocks that ran from springs. Like the Western lantern clocks that inspired their design, the weight driven clocks were often held up by specially built tables or shelves that allowed the weights to drop beneath them. Spring driven Japanese clocks were made for portability; the smallest were the size of large watches, and carried by their owners in inro pouches.