On Oct 21, 9:10*am, KC wrote:
=IF($F4="On Board",MAX(0,((S$1-$M4)/7))*Q4,"")

S1= 3/31/2010
M4= 10/15/2009
Q4= $573

How can I fix the formula above so it will correctly calculate the cost
based on a 2009 date, or a 2010 date. *Currently, the formula only works if
M4 has a date of 2010.

This is not what you want. I am not sure what that is but this
formula says that if F4 = On Board then find the max of 0 or the
difference between 2 dates / 7 * Q7. If it does not = On Board then
return a blank cell. More data woudl be helpful.
Jay