Conditional Formatting for Calendar

Hi,

I've been looking and reading on the forum for answers to a slight problem I have. As I haven't found any solution i'm going to ask in a thread instead.

I want to create an event calendar. Which means I would like a conditional formatting to color cells that are seen as a specific date which is shown at the top of the column. So if an event is from 3rd of march to 5th of march the cells of march 3-5 are colored in a defined color.

I know how to color a cell if its text matches another box (simple =if forumla), but not how I can program it to color cell nr 3 (which is empty) if these dates match or is between the two defined dates of the event.

ive attached the excel file so you can see!

Thanks