I am trying to calculate the difference between two dates and have that
diveded by seven, (e.g. 7/XX-XX) and remove any answers that sum less than 0.5

So far I have the below formula, but it returns an "ERROR" where there is
blank cells. I think that is because of the zero in the ...C3-D3<0),..
section

=IF(AND(ISNUMBER(C3),ISNUMBER(D3),C3-D3<0),IF(ROUND(7/(C3-D3),5)0.5,ROUND(7/(C3-D3),5),""))

has anyone any ideas please??

Ted.