I'd set up three fields for this that all extract different parts of the current date:
cDayNumb: Let ( d = Day ( get ( currentdate ) ) ;
Case ( d = 1 ; "First" ;
d = 2 ; "Second" ;
d = 3 ; " Third" ;
//and so forth
"Thirtyfirst" ) )
cMonth : MonthName ( Get ( CurrentDate ) )
cYear: "Two Thousand " & Let ( y = Year ( Get ( CurrentDate ) ) ;
Case ( y = 2010 ; "Ten" ;
y = 2011 ; "Eleven" ;
// and so forth ))
Once you have these three parts working for you, you can either define a third calculation field that combines them or you can insert these as merge fields into layout text to get your full sentence.
There's also a knowledgebase article that shows how to convert nearly any number into word form that could be adapted for this, though it seemed like overkill for this specific use.