Where do I need to press ctrl + shift + enter? I have tried this in the cell which contains the formula but nothing has happened.
I have done that and the curly braces are now around the formula, but the result is still showing as #VALUE! Would it help if I gave you the formula?
I have uploaded the file - the 6 digit ID is 514426.
The formula is =SUMPRODUCT((Income!$A$3:$A$334>=DATEVALUE(D1))*(Income!$A$3:$A$334<=DATEVALU(D2)),Income!$AA$3:$AA$334)
Yes it is.