code: public static int dayOfWeek(){
  		setTime();
  		int dayofweek = cal.get(Calendar.DAY_OF_WEEK) - 1;
  		if (dayofweek == 0) {
  			dayofweek = 7;
  		}
  		return dayofweek;
  	}
docs: 某周的第几天
  SUN	= 7 MON = 1	TUE = 2	WED = 3
  THU = 4	FRI = 5	SAT = 6
  @return