The traditional system of Japanese time keeping is based on local solar time as opposed to mean/civil time. Like a 24 hour clock, the wadokei (literally “Japanese Clock”), is mono-diurnal. I coin this term to describe a clock face whose hour hand rotates once per day. The 12 hour system, in contrast, is bi-diurnal. The Italians experimented with a 6 hour clock face during the 18th century and this would be tetra-diurnal. Unlike the Western 24 hour clock, the wadokei is divided into 12 sections—each named after a sign of the Chinese zodiac. Very unlike the Western system, these hours are of uneven length. The Japanese clocks are very elegant in design and are fascinating to contrast with the European style.