function IsMMDDYY(
    const AData: String; 
    const ADelin: String
): Boolean;

Boolean - True when the string contains a valid date.

IsMMDDYY is a Boolean function used to determine if the string in AData represents a valid date. ADelin indicates the delimiter(s) expected between the month, day, and year components of the date value. 

IsMMDDYY expects the month to be the initial component in the date string, and must be in the range 1..12 inclusive. Left-padding with Zero (0) is optional. 

IsMMDDYY expects the day value to be the next component in the date string, and must be in the range 1..31 inclusive. Left-padding with Zero (0) is optional. 

IsMMDDYY expects the year value to be the next component in the date string, and must be a valid numeric value. 

IsMMDDYY returns True when AData contains a valid date value using the specified delimiters.