In Java 15 solution

public static String findDay(int month, int day, int year) {
    Calendar calendar = Calendar.getInstance();
    var dayOfWeek = calendar.get(calendar.DAY_OF_WEEK);
    String[] names = new String[] {"SUNDAY", "MONDAY", "TUESDAY", "WEDNESDAY", "THURSDAY", "FRIDAY", "SATURDAY"};
    return names[dayOfWeek - 1];
}