Change value of cell based on a drop down menu option.

Hello guys,

I need some help, I'm currently making an excel sheet that requires certain information. When a "DAY" is picked from a drop down menu, I would like for the column that is marked as "STATUS" reflect the information of "RDO" when a day of the week falls within the days off from the adjacent "DAYS OFF" column.

Example: If Saturday is picked from the menu, then the status of the employees whose days off are Saturdays ( F/Sa, Sa/Su ) will show as "RDO" (Regular day off).

DAY
SATURDAY (<- Drop down menu with all days of the week)

Days off STATUS
M/Su
F/Sa RDO
Tu/W
Th/F
Sa/Su RDO

If any one can please advise me I will truly appreciate it.

Thank you!