i need a train leaving cambridge i want to be at my designation by 17:45 .
{'service': 'train', 'act': 'request', 'slot_name': 'dest', 'value': '?'} {'service': 'train', 'act': 'request', 'slot_name': 'day', 'value': '?'}
what is your destination site and what day are you planning to travel on ?