ospel ▁use ▁two ▁distinct ▁cal end ars ▁( the ▁official ▁Jewish ▁lun ar ▁calendar , ▁and ▁what ▁is ▁today ▁the ▁Sam ar itan ▁lun ar ▁calendar , ▁the ▁latter ▁used ▁in ▁Jesus ' ▁day ▁also ▁by ▁the ▁Ess enes ▁of ▁Q um ran ▁and ▁the ▁Ze al ots ). ▁Hum ph rey ' s ▁proposal ▁was ▁preced ed ▁in ▁ 1 9 5 7 ▁by ▁the ▁work ▁of ▁An nie ▁Ja ub ert ▁who ▁suggested ▁that ▁Jesus ▁held ▁his ▁Last ▁Su pper ▁at ▁Pass over ▁time ▁according ▁to ▁the ▁Q um ran ▁solar ▁calendar . ▁Hum ph re ys ▁reject s ▁Ja ub ert ' s ▁conclusion ▁by ▁demonstr ating ▁that ▁the ▁Q um ran ▁solar ▁reck oning ▁would ▁always ▁place ▁Jesus ' ▁Last ▁Su pper ▁after ▁the ▁Jewish ▁Pass over , ▁in ▁contradiction ▁to ▁all ▁four ▁g osp els . ▁Instead , ▁Hum ph re ys ▁points ▁out ▁that ▁the ▁Ess ene ▁community ▁at ▁Q um ran ▁addition ally ▁used ▁a ▁lun ar ▁calendar , ▁itself ▁evidently ▁based ▁on ▁the ▁Egypt ian ▁lit urg ical ▁lun ar ▁calendar . ▁Hum ph re ys ▁suggests ▁that ▁the ▁reason ▁why ▁his ▁two - calendar ▁solution ▁had ▁not ▁been ▁discovered ▁earlier ▁is ▁( a ) ▁w ides p read ▁scholar ly ▁ignor ance ▁of ▁the ▁existence ▁of ▁the ▁Egypt ian ▁lit urg ical ▁lun ar ▁calendar ▁( used ▁alongside ▁the ▁well - known ▁Egypt ian ▁administrative ▁solar ▁calendar , ▁and ▁pres umably ▁the ▁basis ▁for ▁the ▁ 1 3 th - century ▁BC ▁Jewish ▁lun