how to resolve this nondeterminism between INT and DATE?

Hello,
I've a problem resolving a nondeterminism between INT and DATE
('mm'-'dd'-'yy') in ANTLR. Could you give me a hint please.
thanks
Oliver

--- grammar ---

....
  
class KlarfLexer extends Lexer;

options 
{
    k=3;        
    ex****tVocab=KLARF;
    charVocabulary='\u0000'..'\u007F';
    caseSensitive=false;
    caseSensitiveLiterals=false;
}

INT
        : ( '0'..'9' )+
;

....

DATE
        : ( ('0'..'9')('0'..'9') '-')=>
                ('0'..'9')('0'..'9') '-' ('0'..'9')('0'..'9') '-'
('0'..'9')('0'..'9')
        | { $setType(INT); }
;
 
....