Kanji for Moon — 月

月 is read tsuki on its own and getsu or gatsu in compounds. It means the moon, and also the month — a crescent and a calendar unit in the same four strokes, since months were once counted by moons.

The shape is a crescent with two lines inside it, drawn narrow rather than round so it does not collide with 日 (sun). Careful: an almost identical element appears in 服, 育 and 肝, but there it is a squashed 肉 (meat), the flesh radical — same look, unrelated origin.

Autumn moon-viewing, 月見 (tsukimi), is a real seasonal event in Japan, complete with rice dumplings and pampas grass. In everyday use 月 counts the calendar: 一月 (ichigatsu) is January, 今月 (kongetsu) this month, and 月曜日 (getsuyōbi) is Monday, the moon's day.