private String date = "2017-05-21";//
SimpleDateFormat simpleDateFormat;

simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
b11.setOnClickListener(new View.OnClickListener() {
    @Override
public void onClick(View v) {
        try {
            Date date1 = simpleDateFormat.parse(date);
SimpleDateFormat simpleDateFormat = new 
 
SimpleDateFormat("EEEE");
SimpleDateFormat simpleDateFormat2 = new SimpleDateFormat("E");
String s1 = simpleDateFormat.format(date1);
String s2 = simpleDateFormat2.format(date1);
b11.setText(s1 + ":" + s2);
} catch (ParseException e) {
            e.printStackTrace();
}
    }
});
b12.setOnClickListener(new 
 
View.OnClickListener() {
    @Override
public void onClick(View v) {
        Calendar calendar = Calendar.getInstance();
String s1 = "";
        try {
            calendar.setTime(simpleDateFormat.parse(date));
} catch (ParseException e) {
            e.printStackTrace();
}
        if ((calendar.get(Calendar.DAY_OF_WEEK
 
)) == 1) {
            s1 = "週日";
}
        if ((calendar.get(Calendar.DAY_OF_WEEK)) == 2) {
            s1 = "週一";
}
        if ((calendar.get(Calendar.DAY_OF_WEEK)) == 3) {
            s1 = "週二";
}
        if ((calendar.get(Calendar.DAY_OF_WEEK)) == 4) {
            s1 = "週三";
}
        if ((calendar.get(Calendar.DAY_OF_WEEK)) == 5) {
            s1 = "週四";
}
        if ((calendar.get(Calendar.DAY_OF_WEEK)) == 6) {
            s1 = "週五";
}
        if ((calendar.get(Calendar.DAY_OF_WEEK)) == 7) {
            s1 = "週六";
}
        b12.setText(s1);
}
});