Finde ugedag vha. af dato

SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
Date date = sdf.parse("25-12-2004");
Calendar cal = Calendar.getInstance();
cal.setTime(date);
int ugeDag = cal.get(Calendar.DAY_OF_WEEK);
//http://java.sun.com/j2se/1.4.2/docs/api/java/util/Calendar.html#DAY_OF_WEEK

Tak :)