The Japanese system of dividing the day, which was similar to that used in Europe in the Middle Ages, continued in use until 1873. The daylight period, including a considerable amount of twilight, was divided into six equal parts, and the period of darkness also into six parts. These hours were numbered, from midnight to noon, 9, 8, 7, 6, 5, 4, and again in the same sequence from noon to midnight. Japanese clocks were therefore designed to indicate and strike on this system. The length of twilight included in the Japanese day may be judged from the fact that some clock dials show that (in approximately 35?latitude) 'day' and 'night' were of about equal length in winter while in summer 'day' was over twice as long as 'night'.