Acustomisatraditionalpractice--amodeofinpidualbehaviororahabitofsociallife--thatistransmittedbyword-ofmouthorimitation,theningrainedbysocialpressure,commonusage,andparentalauthority.Whencustomsareassociatedwithholidaystheybecomecalendarcustoms1,andwhensucheventsarecelebratedannuallybyawholecommunitytheybecomefestivals.