Where does “一月” come from?

一月 (Old Japanese) comes from Old Japanese 月, from Proto-Japonic tukuy, from Proto-Japonic tuku.

一月 (Old Japanese): one month

Definitions

  1. one month

Ancestry of “一月”, step by step

一月 traces back through two separate lines of ancestry.

via Old Japanese 月

StepLanguageWordMeaning
1Old Japanese月the moon; a month; a menstrual cycle,...
2Proto-Japonictukuymoon
3Proto-Japonictuku—

via Old Japanese 一

StepLanguageWordMeaning
1Old Japanese一—
2Proto-Japonic*pitəone
Every word from Proto-Japonic tuku →Every word from Proto-Japonic tukuy →Every word from Old Japanese 月 →
一月 — Etymology, Origin & Word History | Etymology Explorer