Does the author uses the phrase “the autumn towards the close of day” as a symbol of death, war, night, or fall? What does fishing symbolize in this story (peace, family, friendship, or danger)?

This quotation comes from the story "Two Friends" by Guy de Maupassant. This story concerns two friends who used to meet each other regularly on Sundays to fish before the Franco-Prussian war broke out; the core action of the story focuses on their decision to meet up again during the war. They decide to return once more to their old fishing spot, and there they are accused of espionage by Prussian soldiers.
The phrase "in the autumn, toward the close of day," is used primarily in a literal sense: it describes the "glorious spectacle" of the sun setting at the end of the day which Monsieur Sauvage would sometimes remark upon when the two men's fishing trips were a regular occurrence. As such, it represents, straightforwardly, both night and fall. On a symbolic level, however, this spectacle, with the river tinged with red and the "leaves . . . already turning at the first touch of winter," could be seen to represent the coming war that will put an end to the fishing trips and jollity. The autumnal scene depicted marks the end of the retrospective section which sets the tone for the interaction between Sauvage and Morissot before war came.
For Morissot and Sauvage, fishing represents the bond of friendship between them. At the end of the story, before the men are shot, the last thing Morissot sees before he bids goodbye to his friend is "the still quivering fish glisten[ing] like silver." Throughout the early part of the story, the two men wonder when they will be able to fish again; the idea of fishing reminds them of peacetime, but the act of fishing represents their connection to each other insofar as they want to fish even while knowing that it is dangerous.