用on。

例句：

1. 全世界的華人在陰歷一月十五號(hào)都會(huì)慶祝元宵節(jié)。Lantern Festival is celebrated on the fifteenth day of the first lunar month every year by Chinese people around the world.2.常在陰歷年的第一個(gè)月的第十五天慶祝。It is celebrated on the fifteenth day of the first month of the lunar year.