Pickup window
A pickup window is a span of days, not an hour. The driver may arrive on any day inside it. A tighter promise has to name the day and what happens if the truck misses it.
The pickup window is the range of dates the carrier may collect the car. Companies often describe it as a span of days, not an hour. Your contract controls the span you actually have. You need to be reachable, with the car ready, through the whole window. "Today" in a morning text means that day only if the dispatch sheet says so. The earliest day you can let the car go is the first available date, which is not this window.
What a tighter promise has to include
If you need one date, the contract has to name the date and what you get if the truck does not come: a fee returned, a different truck, or only an apology. The adjective in an ad is not that clause. Ask for the sentence before you pay extra for a tighter window. Expedited service is a different product, with its own price.
How it differs from the first available date
The first available date is the earliest day you can release the car. The window begins on that day or later, when a carrier accepts. A quote form that asks only for the first available date has not given you an appointment. RideShipper does not set the window. The carrier that accepts the load does.