instruction: what do you have on monday from DFW to OAKLAND california
response: SELECT DISTINCT flight.flight_id FROM airport, airport_service, city, date_day, days, flight WHERE (city.city_code = airport_service.city_code AND city.city_name = 'OAKLAND' AND date_day.day_number = 21 AND date_day.month_number = 2 AND date_day.year = 1991 AND days.day_name = date_day.day_name AND flight.flight_days = days.days_code AND flight.to_airport = airport_service.airport_code) AND airport.airport_code = 'DFW' AND flight.from_airport = airport.airport_code