Need help conditional formatting a column with formulas

[fumusic]

Please help?! I have 3 columns with Start Date, Target Date, and Number of working days. There is a formula in the Working days column to produce the values.
I want to condition format the Working days column using the traffic light icons so that:
if the working days are over the target date then red traffic light icon,
if the working days are equal to the target date then amber traffic light icon,
if the working days are under the target date then green traffic light icon,
if there is no start date, then all the rows should be blank, so no traffic light icon,
I need to see the values for the number of working days as well as the traffic light icons.
I have attached my worksheet for you to work on. If you could let me know how you achieved this it would be much appreciated.