Thecustomofascendingaheighttoavoidepidemicswaspasseddownfromlongtimeago.Therefore,theDoubleNinthFestivalisalsocalled"HeightAscendingFestival".Theheightpeoplewillreachisusuallyamountainoratower.Ancientliteraryfigureshaveleftmanypoemsdepictingtheactivity.Eventoday,peoplestillswarmtofamousorlittleknownmountainsonthisday.
The9thdayofthe9thlunarmonthisthetraditionalChongyangFestival,orDoubleNinthFestival.ItusuallyfallsinOctoberintheGregoriancalendar.InanancientandmysteriousbookYiJing,orTheBookofChanges,number"6"wasthoughttobeofYincharacter,meaningfeminineornegative,whilenumber"9"wasthoughttobeYang,meaningmasculineorpositive.SothenumbernineinbothmonthanddaycreatetheDoubleNinthFestival,orChongyangFestival.ChonginChinesemeans"double."