The story is set in New York at 10 o’clock at night, during the early twentieth century.
The story is set at night. In fact, we know that it is ten o'clock. Also, it was published in 1906, so it probably takes place around then. We know that the men are meeting in New York City.
He and I were raised here in New York, just like two brothers, together. I was eighteen and Jimmy was twenty. The next morning I was to start for the West to make my fortune.
The story action is happening on a street. When the story starts, Bob is standing in front of a hardware store that used to be a diner. He has agreed to meet his friend Jimmy there. It is a very old date, but Bob knows Jimmy will keep it. In fact, Jimmy does keep it. Bob talks to Jimmy for most of the story. He just doesn’t know he is talking to Jimmy, because Jimmy doesn’t identify himself. Jimmy is a cop, and he is suspicious of Bob.
The neighborhood might have been nice once, but it is a bit sketchy now. Jimmy was on patrol when Bob showed up, out of habit. He watches him, in the doorway of the darkened hardware store.
The vicinity was one that kept early hours. Now and then you might see the lights of a cigar store or of an all-night lunch counter; but the majority of the doors belonged to business places that had long since been closed.
Since most of the stores on the street are not open, it is not well lit. Jimmy and Bob talk, and then Jimmy leaves. He goes and gets another cop who comes back and pretends to be him. This cop talks to Bob until they walk to a corner, where there is a drug store with brighter lights. Then Bob realizes he is not talking to Jimmy. The cop then tells him he is under arrest, and gives him a note from Jimmy explaining that he recognized him but did not want to arrest him himself.
Setting the story in a big city at night makes it more believable. You can see how people walking by would not notice or care about what goes on between two men having a conversation in the dark, or would not want to get involved. Also, things change a lot in cities, maybe more than small towns. The story of the cop and the crook is ironic, but the big city backdrop makes it classic.