noun
last day of March; last day of the third lunar month (end of spring)
A traditional seasonal term. In the modern calendar it refers to March 31st; in the old lunar calendar it marked the end of spring. Often used in haiku and classical contexts.
三月尽の今日、桜もすっかり散ってしまった。
Today is the last day of March, and the cherry blossoms have completely fallen.
旧暦の三月尽は春の終わりを告げる日だった。
The last day of the third lunar month was the day that announced the end of spring.