YEAR(A3)&"年第"&INT((A3-DATE(YEAR(A3)-1,12,31))/7)+1&"周"
=IF(WEEKNUM(A1,2)<10,RIGHT(YEAR(A1),2)&"年第0"&WEEKNUM(A1,2)&"周",RIGHT(YEAR(A1),2)&"年第"&WEEKNUM(A1,2)&"周")
=IF(WEEKNUM(A1,2)<10,RIGHT(YEAR(A1),2)&"0"&WEEKNUM(A1,2),RIGHT(YEAR(A1),2)&WEEKNUM(A1,2))
=TEXT(B2,"yy")&TEXT(B2,"MM")&"（"& TEXT(B2,"yy")&"第" &WEEKNUM(B2)&"周)"