Here is what I have:

=SUMPRODUCT(--(TEXT(DATE(YEAR(N(OFFSET(H49:BG49,0,{0,1,4,7,11,15,16,20,24,25,29,33,34,38,42,43,47,51},1,1))),
MONTH(N(OFFSET(H49:BG49,0,{0,1,4,7,11,15,16,20,24,25,29,33,34,38,42,43,47,51},1,1))),1),"yymm")=T EXT(TODAY(),"yymm")))

Basically this sums all dates that fall this month across a bunch of cells. How can I change this to sum all dates falling next month?