String s = "2004-11-23";
DateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date date = null;
try {
date = sdf.parse(s);
} catch (ParseException e) {
e.printStackTrace();
}
GregorianCalendar calendar = new GregorianCalendar();
calendar.setTime(date);
int result = calendar.get(Calendar.DAY_OF_WEEK);
System.out.println(result);