- 三九天 sānjiǔtiān midwinter daysthe twenty-seven days after the Winter Solstice, reputed to be the coldest days of the year
- 九天揽月 jiǔtiānlǎnyuè reach for the stars(idiom) to reach for the stars (to achieve a great feat)
- 九天玄女 Jiǔtiān Xuánnǚ Xuan NüXuan Nü, a goddess in Chinese mythology and Taoism
- 数九天 shǔjiǔtiān coldest winter daysthe nine nine-day periods after the winter solstice, traditionally the coldest time of year