=IF(MONTH(A1)=1
,IF(DAY(A1)=1,"元日"
,IF(AND(DAY(A1)=2,WEEKDAY(A1)=2),"振替休日"
,IF(AND(DAY(A1)>7,DAY(A1)<=14,WEEKDAY(A1)=2),"成人の日",""))),
IF(MONTH(A1)=2
,IF(DAY(A1)=11,"建国記念の日"
,IF(AND(DAY(A1)=12,WEEKDAY(A1)=2),"振替休日"
,IF(DAY(A1)=23,"天皇誕生日"
,IF(AND(DAY(A1)=24,WEEKDAY(A1)=2),"振替休日","")))),
IF(MONTH(A1)=3
,IF(DAY(A1)=(INT(YEAR(A1)*0.2422+36.3)-INT(YEAR(A1)/4)),"春分の日"
,IF(AND(DAY(A1)=(INT(YEAR(A1)*0.2422+37.3)-INT(YEAR(A1)/4))
,WEEKDAY(A1)=2),"振替休日","")),
IF(MONTH(A1)=4
,IF(DAY(A1)=29,"昭和の日"
,IF(AND(DAY(A1)=30,WEEKDAY(A1)=2),"振替休日","")),
IF(MONTH(A1)=5
,IF(DAY(A1)=3,"憲法記念日"
,IF(DAY(A1)=4,"みどりの日"
,IF(DAY(A1)=5,"こどもの日"
,IF(AND(DAY(A1)=6,WEEKDAY(A1,3)<3),"振替休日","")))),
IF(MONTH(A1)=6,"",
IF(MONTH(A1)=7
,IF(AND(DAY(A1)>14,DAY(A1)<=21,WEEKDAY(A1)=2),"海の日",""),
IF(MONTH(A1)=8
,IF(DAY(A1)=11,"山の日"
,IF(AND(DAY(A1)=12,WEEKDAY(A1)=2),"振替休日","")),
IF(MONTH(A1)=9
,IF(AND(DAY(A1)>14,DAY(A1)<=21,WEEKDAY(A1)=2),"敬老の日"
,IF(AND(DAY(A1)=(INT(YEAR(A1)*0.2422+37.7)-INT(YEAR(A1)/4))
,WEEKDAY(A1)=3),"国民の休日"
,IF(DAY(A1)=(INT(YEAR(A1)*0.2422+38.7)-INT(YEAR(A1)/4)),"秋分の日"
,IF(AND(DAY(A1)=(INT(YEAR(A1)*0.2422+39.7)-INT(YEAR(A1)/4))
,WEEKDAY(A1)=2),"振替休日","")))),
IF(MONTH(A1)=10
,IF(AND(DAY(A1)>7,DAY(A1)<=14,WEEKDAY(A1)=2),"スポーツの日",""),
IF(MONTH(A1)=11
,IF(DAY(A1)=3,"文化の日"
,IF(AND(DAY(A1)=4,WEEKDAY(A1)=2),"振替休日"
,IF(DAY(A1)=23,"勤労感謝の日"
,IF(AND(DAY(A1)=24,WEEKDAY(A1)=2),"振替休日","")))),
IF(MONTH(A1)=12,"",))))))))))))