When your client books your services, they are asked to pick a preferred date and time window as part of the checkout process. Once you receive the order, you can then communicate with your client to figure out the exact timing.
Our philosophy is to get the order first, and then allow you to work directly with your client to figure out a time that works for both of you. This also gives you flexibility to manage your schedule the way you want. If you can't find a time that works for both of you, you can always cancel the order.