Double Ninth Festival

The Double Ninth Festival (Chung Yeung Festival in Hong Kong, Vietnamese: Tết Trùng Cửu), observed on the ninth day of the ninth month in the Chinese calendar, is a traditional Chinese holiday, mentioned in writing since before the East Han period (before AD 25).

According to the I Ching, nine is a yang number; the ninth day of the ninth lunar month (or double nine) has too much yang (a traditional Chinese spiritual concept) and is thus a potentially dangerous date. Hence, the day is also called "Double Yang Festival" (重陽節). To protect against danger, it is customary to climb a high mountain, drink chrysanthemum wine, and wear the zhuyu (茱萸) plant, Cornus officinalis. (Both chrysanthemum and zhuyu are considered to have cleansing qualities and are used on other occasions to air out houses and cure illnesses.) On this holiday some Chinese also visit the graves of their ancestors to pay their respects. People eat Chongyang Cake on the day.

Origin
One day a man named Huan Jing believed that a monster bringing pestilence was coming. He told his countrymen to hide on a hill while he went to defeat the monster. Later, people celebrated Huan Jin's defeat of the monster on the ninth day of the ninth lunar month.

In 1966, the Republic of China (Taiwan) rededicated the holiday as "Senior Citizens' Day", underscoring one custom as it is observed in China, where the festival is also an opportunity to care for and appreciate the elderly.

Double Ninth may have originated as a day to drive away danger, but like the Chinese New Year, over time it became a day of celebration. In contemporary times it is an occasion for hiking and chrysanthemum appreciation. Stores sell rice cakes (糕 "gāo", a homophone for height 高) with mini colorful flags to represent zhuyu. Most people drink chrysanthemum tea, while a few traditionalists drink homemade chrysanthemum wine. Children learn poems about chrysanthemums, and many localities host chrysanthemum exhibits. Mountain climbing races are also popular; winners get to wear a wreath made of zhuyu.

Poem
There is an often-quoted poem about the holiday: 九月九日憶山東兄弟

jiǔ yuè jiǔ rì yì shān dōng xiōng dì

獨在異鄉為異客,

dú zài yì xiāng wéi yì kè

每逢佳節倍思親.

měi féng jiā jié bèi sī qīn

遙知兄弟登高處,

yáo zhī xiōng dì dēng gāo chù

遍插茱萸少一人.

biàn chā zhū yú shǎo yī rén

- "Double Ninth, Missing My Shandong Brothers" — Wang Wei (王維), Tang Dynasty English:
 * As a lonely stranger in a strange land,
 * At every holiday my homesickness increases.
 * Far away, I know my brothers have reached the peak;
 * They are planting flowers, but one is not present.