0 the day on which an important event happened in a previous year -- 週年紀念；週年紀念日
We always celebrate our wedding anniversary with dinner in an expensive restaurant. 我們總是去豪華飯店就餐來慶祝我們的結婚紀念日。
Tomorrow is the 30th anniversary of the revolution. 明天是革命30週年紀念日。
We are planning a dinner to celebrate the 50th anniversary of the founding of the company.
Tomorrow's parade will mark the 50th anniversary of the battle.
On this anniversary of the tragedy we remember the living as well as the dead.
It would be a pity to have to wait for another anniversary to prompt further performances.
The five hundredth anniversary of his birth occurs this year.
As a related special event, the 20th anniversary of two-level morphology was celebrated.
