zhōu nián jì niàn rì

anniversary

In Chinese, '周年纪念日' refers to the celebration of a date marking a significant event that occurred on the same date in a previous year. It is commonly used to commemorate personal events such as weddings or relationships, as well as broader occasions like a company's founding. The term combines '周年' meaning 'anniversary' and '纪念日' meaning 'commemoration day'.