On the 28th, TWICE official SNS posted several photos of the members' messages and recent events celebrating the debut 1500 days.
About TWICE
Twice is a South Korean girl group formed by JYP Entertainment. The group is composed of nine members: Nayeon, Jeongyeon, Momo, Sana, Jihyo, Mina, Dahyun, Chaeyoung, and Tzuyu.
 Wikipedia