I have the following formula already working:

=P19-(IF(AND(P4:P18)=7,0.5,0)*P22)-IF(P4<=5,P4,P4-0.5)-IF(P14<=5,P14,P14-0.5)

currently I have to manually correct p4 and p14 to match if the row where 4
and 14 are Sundays. I.e. If during this payroll, Sunday falls on A5 I
should manually change p4 to p5.

How could I do this automatically, if my dates are in Column A?