CF using date to change Font/Backgroundcolor to another cell

Hello,

Good day,

can you help me how can I change the font/background color of another cell base from the list in another cell.

Example in A1, i have a list containing Months which is from January to December. Format required is M/DD/YYYY. If i select month of May (5/01/2017) from drop-down list in A1 cell, the b1 cell should have change to my desired font/bakground color.

glad to know your answers. Many Thanks in advance.