RxTimePicker.newInstance()  
        .show(getSupportFragmentManager())  
        .asObservable()  
        .subscribe(timeInfo -> {  
            String msg = timeMessage(timeInfo);  
            tv_date.setText(msg);  
  });

RxDatePicker.newInstance()  
        .minDate(System.currentTimeMillis() - (4 * 24 * 60 * 60 * 1000)) // 4 days  
        .maxDate(System.currentTimeMillis() + (4 * 24 * 60 * 60 * 1000))  
        .show(getSupportFragmentManager())  
        .asObservable()  
        .subscribe(dateInfo -> {  
            String msg = dateMessage(dateInfo);  
            tv_time.setText(msg);  
  });

RxDateTimePicker.newInstance()  
        .minDate(System.currentTimeMillis() - (4 * 24 * 60 * 60 * 1000)) // 4 days  
        .maxDate(System.currentTimeMillis() + (4 * 24 * 60 * 60 * 1000))  
        .show(getSupportFragmentManager())  
        .asObservable()  
        .subscribe(dateTimeInfo -> {  
                    String msg = new StringBuilder()  
                            .append(dateMessage(dateTimeInfo.getDateInfo()))  
                            .append("\n")  
                            .append(timeMessage(dateTimeInfo.getTimeInfo()))  
                            .toString();  
                    tv_dateTime.setText(msg);});