On the ninth day of the ninth month in the Chinese lunar calendar, people celebrate the Double Ninth Festival. Nine is a yang number（a traditional Chinese spiritual concept）in The Book of Changes, so Double Ninth is called Chongyang. Climbing the mountains is one of the most popular traditions on that day. In September the sky is high and the air is fresh, and climbing the mountains is helpful to keep physical fitness. The tradition of eating double-ninth cakes is associated with climbing the mountains. As a kind of festival foods, the double-ninth cake was first used to celebrate the autumn harvest. Later, it developed into the custom of climbing the mountains and eating double-ninth cakes, which means that our life will become better and better. Because double ninth sounds like longevity（jiujiu in Chinese）, the Double Ninth Festival nowadays has been given a new meaning — Seniors' Day.
每年农历九月初九，人们会庆祝重阳节（the Double Ninth Festival）。《易经》（The Book of Changes）认为数字“九”是阳数，故“重九”也叫“重阳”。登高是最受欢迎的重阳节传统之一。九月天空高远，空气新鲜，在这样的日子登高有助于保持身体健康。吃重阳糕（double-ninth cake）跟登高有关。重阳糕作为节日食品最初用来庆祝秋收，后来发展成登高、吃重阳糕的习俗，寓意是我们的生活将越来越好。由于“九九”谐音“久久”，重阳节如今已被赋予新的涵义——老人节。
