sounds extremely easy but its NOT!

i want to create a drop down box in excel for the months 1-12, i then want the dropdown selection (ie. march) to be able to generate d-mmm-yy for all 31 days and have the day (ie mon tues wednes) in the next column

so,
A1 | Jan-Dec dropdown
B1-31 | d-mmm-yy
C1-31 | dddd


please help me do this