This story takes place sometime between 1950 and 1953. We know this because it is taking place during the Korean War, which took place after World War II. The first paragraph of the story gives readers an important detail about the setting.
The northern village at the border of the Thirty-eighth Parallel was snugly settled under the high, bright autumn sky.
That 38th parallel is important because that is the dividing line between North Korea and South Korea. During the Korean war, villages that were located near that line repeatedly changed hands. Based on the wording of the first paragraph, I think the narrator is telling readers that the story is taking place in what was at the time South Korea. That is why it is a northern village. If the village was part of North Korea, then that village would be a southern village. Regardless, readers know that the starting village is one that is on the front lines of the conflict. The two main characters grew up in that village, and they wound up on opposite sides of the conflict. That makes sense based on the village's location. Many people were probably pro-north, while others were likely pro-south.
The bulk of the story does not take place in the village. Most of the story takes place on the road from the village. Songsam is taking Tokchae to another police station, but he decides to free his boyhood friend before reaching their destination.