Japanese clock facts for kids

Edo period clock in collection of Tokyo National Science Museum.

The Japanese clock is a device made to tell the time according to Japanese tradition. These clocks were introduced to Japan via Jesuit missionaries in the 16th century. In 1612, the clock-maker of Philip II of Spain created a working timepiece which became a gift for Tokugawa Ieyasu.

One of the major features of the Japanese clock is that it has a mechanism for measuring unequal temporal hours. Usual clocks tells hours at same intervals, but in the Japanese traditional timekeeping practice, a day had six daytime units from sunrise to sunset and six night units from sunset to sunrise. The the Japanese clock was designed to adapt to this practice.

The traditional Japanese time system

Hisashige Tanaka's 1851 myriad year clock displays Japanese, equal hour, and calendar information

Myriad-Year Clock, made by Hisashige Tanaka, 1851

The typical clock had six numbered hours from 9 to 4, which counted backwards from noon until midnight; the hour numbers 1 through 3 were not used in Japan for religious reasons, because these numbers of strokes were used by Buddhists to call to prayer. The count ran backwards because the earliest Japanese artificial timekeepers used the burning of incense to count down the time.

In addition to the numbered temporal hours, each hour was assigned a sign from the Japanese zodiac. Starting at dawn, the six daytime hours were:

From dusk, the six nighttime hours were:

Images for kids

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  Two separate foliot balances allow this 18th-century Japanese clock to run at two different speeds to indicate unequal hours.

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  Drawing of the mechanism of a Japanese clock. Karakuri Zui, 1796.

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  The traditional Chinese 12 Earthly Branches and 24 Cardinal Directions; the 12 Earthly Branches are the basis for the zodiacal assignments of the Japanese hours.

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  European lantern clocks such as this one were the starting point for the design of Japanese clocks.

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  Nichō tenpu yagura-dokei (lantern clock with a double foliot mechanism).

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  Left: Makura-dokei (pillow clock) with music box. Right: Dai-dokei (pedestal clock) with circular balance.

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  Tsurigane-dokei (hanging bell-shaped clock).

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  Taiko-dokei.

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  Wadokei Revision wristwatch that tells Japanese time and modern time by Masahiro Kikuno.

See also

In Spanish: Reloj japonés para niños