DatePickerDialog.OnDateSetListener dateListener1,dateListener2;

dateListener1= new OnDateSetListener(){

            public void onDateSet(DatePicker arg0, int arg1, int arg2, int arg3) {

                          ...

                }
            }

        };
dateListener2= new OnDateSetListener(){
            public void onDateSet(DatePicker arg0, int arg1, int arg2, int arg3) {
                .....
            }
        };

int DATE_PICKER2 = 0;
int DATE_PICKER1 = 1;
@Override
protected Dialog onCreateDialog(int id) {

    switch(id){
        case DATE_PICKER1:
                return new DatePickerDialog(this, from_dateListener, from_year, from_month, from_day);
            case DATE_PICKER2:
                return new DatePickerDialog(this, to_dateListener, to_year, to_month, to_day);
    }
        return null;
}