I’m sure the answer is “some computer algorithm told them to price it this way”, but I was looking up fares on Southwest and a lot of them made no sense. I can understand why early and late flights in the middle of the week are cheapest, but Saturday is almost as cheap as weekdays, except for maybe a random Saturday every month, but Sunday is always extremely expensive. And it’s $10 more to fly from SMF to MSP than MSP to SMF.
And the rental cars- they don’t have 5 or 6 day rentals for some reason. and the weekly rate is about 4.5 days. All in all it’s cheaper by far to take vacations in week spans instead of several days at a time.