IF(B1 = "法定节假日",M3,IF(B1 = "工作日" || B1 = "法定调休"),N3,IF(B1 = "内部调休",O3,""))
IF(B1 = "法定节假日", M3, IF(B1 = "工作日" || B1 = "法定调休", N3, IF(B1 = "内部调休", O3, "")))
if(B1="法定节假日",M3,if(or(B1="工作日",B1="法定调休"),N3,if(B1="内部调休",O3,"")))