<firstday> 			: : = 	0 | 1 | 2 | 3
<secondday> 		: : =	0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
<firstmonth>		: : =	0 | 1
<secondmonth>	: : = 	0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9

<day>			: : = 	<firstday> 	<secondday>
<month>			: : =  <firstmonth> <secondmonth>
<year>			: : =	2009


<datum>			==>	<day>"."<month>"."<year>