I travel several times a year through BWI, DCA, and IAD. I never park at the airport; I always use outside parking lots. Every place I have used charges based on the dates, not the times. They are not very strict about the exact arrival time as long as you pick up on the day of the reservation. However, be warned, this place is different. They charge based on the time you arrive, so make sure to allow sufficient time for delays, luggage pickup, etc. When you are going to put your pickup time. Additionally, other parking lots allow you to extend the parking using the same 3rd party you booked through, but not this one. They don't allow it. They charged $15 plus tax for a few hours' extension, whereas through the original booking platform, it would have only been $10 extra. Furthermore, your car will be parked outside the entire time in a dusty parking lot, so be prepared to pick up a dusty car. It's important to note your car's size pickup truck, SUV, etc, as they charge extra for that as well. Also, make sure not to lose the ticket they give you. While I was there I saw some having trouble getting their car because they lost theirs. My booking through this app costs $16 for Thursday to Sunday. I was charged an additional $17 for arriving after my scheduled time. It's crazy that I paid more for a few hours than for the 4 days my car was there. The total charge was $33 I want to note that I tried several times to contact the app through email, but they were not able to assist me in a timely manner. They responded the day after. When you arrive to drop off the car, they will make you sign a waiver. What are you going to do, leave? Let's be honest, by the time we arrive to drop off the car and see the waiver, we don't have the time to go looking for a new place. So, you don't have a choice but to sign and pray your flight doesn't get delayed. On a positive note, the shuttle service was fast, and the pick-up and drop-off process was quick. I'm giving this place 2 stars due to the overcharge.