This is a question with answer options. Goal: What should I do with my windows during the summer?

Which of the following methods is more reasonable for accomplishing this goal?

Available choices:
* Once the sun goes down and the air cools, it's time to open them up and let some fresh air in.
* Once the sun goes up and the air warms up, it's time to open them up and let some fresh air in....I think the answer is
Once the sun goes down and the air cools, it's time to open them up and let some fresh air in.