I'm not sure how to specify the time period when I want the Rover sitter to stay with the dog the whole weekend. I know of course that she will be leaving the dog in the house and not be there all the time, but I don't know what her hours are and how can I just put Friday morning through Sunday evening?
The only way to communicate your needs is to discuss with potential sitters. Put in the entire time you will be gone, then have a Meet & Greet to go over your expectations and how the sitter proposes to fulfill. Every sitter may do things differently, especially when it comes to engagements involving staying at a dog owner's home. But you need to ask them what they plan to do, how much time they'll spend in your home, etc, Then you tell them what you need them to do. Eventually you'll find someone who will meet your needs.