There are many trains that meet that requirement. Where are you headed?
Hi, I need a train Wednesday that will arrive by 19:45. I'm headed from Cambridge to Broxbourne.
{"__type": "Request", "service": "train", "values": ["destination"]}
{"__type": "Request", "service": "train", "values": ["leave at"]}
When would you like to depart? You can select any hour between 05:01 and 18:01.