Look at SUMPRODUCT rather SUMIFS: it should handle the construct

RIGHT(B1,2)& MID(B1,2,1) > RIGHTt(A1,2)& MID(A1,2,1)

If you use SUMPRODUCT use finite ranges rather than whole column ranges i.e SUMPRODUCT (A2:A5000.....) rather than SUMPRODUCT((A:A ....)


e.g with data to be SUMMED in C1:C4 and DATES in A and B


=SUMPRODUCT((C1:C4)*(RIGHT(B1:B4,2)& MID(B1:B4,2,1) > RIGHT(A1:A4,2)& MID(A1:A4,2,1)))