What is the situational irony in all summer in a day?

Oh, dude, like, the situational irony in "All Summer in a Day" is when the kids on Venus finally see the sun for the first time in seven years, but then Margot, who had been on Earth and missed the sun the most, gets locked in a closet and misses it. It's like, "Wow, what are the odds, right?" So, yeah, that's the ironic twist in that short story.