am looking for a train , it should leave on sunday and should go to stansted airport
{'service': 'train', 'act': 'inform', 'slot_name': 'time', 'value': '28 minutes'} {'service': 'train', 'act': 'request', 'slot_name': 'arrive', 'value': '?'}
what time would you like the train to arrive at cambridge ? keep in mind the train ride duration is approximately 28 minutes .