three months
Refers to a period of three months. Often used in contexts like 'for three months' or 'every three months'.
このプロジェクトは三月かかる。
This project will take three months.
三月に一度、健康診断を
Three months have passed since I moved.
I have a health checkup once every three months.
三月ぶりに友達に会った。
I met my friend for the first time in three months.