{=SUM(E13:AE13*IF(TEXT(E$7:AE$7,"mmmm")=mes,1,0))} gives 15.05767168


{=SUM(E13:AE13*IF(AND(TEXT(E$7:AE$7,"mmmm")=mes,TR UE),1,0))} gives 0

mes is the range name for a cell that contains the name of a month.

The top array formula works as expected, but why does the bottom one
give 0. It should give the same result as the top one as I have only
added TRUE in an AND condition.