I was searching around for rental car prices for a trip I'm taking this weekend, and saw something I've never seen before. The pick-up time made a huge difference in the price quote.
I was looking on Hertz's website, for a rental from Thursday to Monday, and when I searched using their default time of 10am, it gave me a price of $45 a day for a compact car. I searched again, adjusted the pickup/drop-off time to 3 pm and the price fell all the way to $18!
That's a 60% discount by changing the pickup time by 6 hours! Exploring further, I found the price dropped at noon, and then again at 3pm.
I assume the reason is that after noon on Thursday, they shift into Weekend Rates, but its something to keep in mind when you're shopping for the best deal for a rental car.