Wire up DatePicker

AddEntryActivity.java

    private void setDateFields(){
        entryDate.setOnClickListener(this);

        Calendar calendar = Calendar.getInstance();
        datePickerDialog = new DatePickerDialog(mThis, new DatePickerDialog.OnDateSetListener() {
            @Override
            public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
                Calendar newDate = Calendar.getInstance();
                newDate.set(year, monthOfYear, dayOfMonth);
                entryDate.setText(dateFormatter.format(newDate.getTime()));
            }
        }, calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH), calendar.get(Calendar.DAY_OF_MONTH));
    }