it ic ▁communities ▁would ▁chant ▁the ▁entire ▁Ps alter ▁through ▁in ▁a ▁week , ▁so ▁these ▁ps al ms ▁would ▁be ▁said ▁on ▁a ▁regular ▁basis , ▁during ▁the ▁course ▁of ▁the ▁Can on ical ▁hours . ▁ ▁Eastern ▁Christian ity ▁In ▁the ▁Eastern ▁Orth odox ▁Church ▁and ▁those ▁Eastern ▁Catholic ▁Church es ▁which ▁follow ▁the ▁By z antine ▁R ite , ▁the ▁Songs ▁of ▁D eg rees ▁( G reek : ▁an ab ath mo i ) ▁make ▁up ▁the ▁E igh teenth ▁Kath is ma ▁( div ision ▁of ▁the ▁Ps alter ), ▁and ▁are ▁read ▁on ▁Friday ▁even ings ▁at ▁V es pers ▁throughout ▁the ▁lit urg ical ▁year . ▁The ▁Kath is ma ▁is ▁divided ▁into ▁three ▁sections ▁( called ▁st ases ) ▁of ▁five ▁ps al ms ▁each . ▁ ▁During ▁Great ▁L ent ▁the ▁E igh teenth ▁Kath is ma ▁is ▁read ▁every ▁week day ▁( M ond ay ▁through ▁Friday ▁evening ) ▁at ▁V es pers , ▁and ▁on ▁Monday ▁through ▁Wed nes day ▁of ▁Holy ▁Week . ▁In ▁the ▁S lav ic ▁usage ▁this ▁Kath is ma ▁is ▁also ▁read ▁from ▁the ▁ap od osis ▁of ▁the ▁Ex alt ation ▁of ▁the ▁Cross ▁up ▁to ▁the ▁for ef east ▁of ▁the ▁N ativity ▁of ▁Christ , ▁and ▁from ▁the ▁ap od osis ▁of ▁The oph any ▁up ▁to ▁the ▁Sunday ▁of ▁the ▁Pro dig al ▁Son . ▁The ▁reason ▁for ▁this ▁is ▁that ▁the ▁night s ▁are ▁longer ▁in ▁winter , ▁especially ▁in ▁the ▁northern