Please try this formula where E1 = a date (to match column A) and F1 = a text (to match column B).

=SUMPRODUCT(($A$2:$A6=$E$1)*($B$2:$B$6=$F$1)*($C$2:$C$6))

When you expand the ranges to suit your needs – I would use named ranges for better transparency and easier management – make sure that all 3 ranges are of identical size.