calendar.add(Calendar.DAY_OF_MONTH, 1);
if(dateTimeTextView.getId() == R.id.date_start)
((TextView)findViewById(R.id.date_end)).setText(String.format("%4d-%2d-%2d", calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH), calendar.get(Calendar.DAY_OF_MONTH)));
calendar.add(Calendar.DAY_OF_MONTH, 1);
if(dateTimeTextView.getId() == R.id.date_start)
((TextView)findViewById(R.id.date_end)).setText(String.format("%4d-%2d-%2d", calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH), calendar.get(Calendar.DAY_OF_MONTH)));