Season. Japan has four seasons: spring, summer, autumn, and winter (春・夏・秋・冬). Being located in the northern hemisphere the seasons in Japan follow the same pattern as Europe and North America.
Up until 1872, the start of the Meiji period, Japan used to have "24 seasons", the year being divided into 24 equal parts (nijuushisekki・二十四節気・にじゅうしせっき | nijuushiki・二十四気・にじゅうしき).
Up until the same time the Japanese also used a different (temporal) system for timekeeping. The periods from sunrise to sunset and from sunset to sunrise were each divided into 6 equal parts. Since the time between sunset and sunrise changes as the length of the day changes, the duration of the 6 equal parts for the day and night cycle also changed. Japanese mechanical clocks of the period (wadokei・和時計) used adaptions of western clocks to show the variable Japanese time.