0 (the celebration of) the day on which an important event happened many years ago -- (重要事件的)周年紀念;紀念大慶
the Queen's diamond jubilee 女王登基60周年紀念
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
再长的路,一步步也能走完,再短的路,不迈开双脚也无法到达。