Why is it not accepting my camper’s birthday?

The birthday must be entered in the proper format

1) Enter the birthday as Jan-03-2005. Do not enter Jan-3-2005 or Jan-03-05.

2) You may also enter the date as MM/DD/YY

3) Months must be entered as 3 letters only not 4. September must be Sep not Sept and July must be Jul not July.