Tricky AND formula

[Brian Sells]

I have a Gantt style sheet that is for tracking projects. I have an AND formula that highlights cells according to the number of days but when the cell that has the number of days is blank, it still highlights one cell like there is a day. I was wondering if there is a way to nest an IFBLANK or something else in with the formula. This is the formula for the cell: =(IF(AND(F$5>=$D6,F$5<=$E6),"X","")) and cell C6 is where I input the number of days for the task. D6 and E6 have the dates in them and adjust according to the number of days entered in C6. Any help would be greatly appreciated.

 

[Joe4]

You can test for something empty/is blank like this:

C6=""