If a buyer requests a time that you're not available, offer them 2 other times that you're available. You don't need to give a specific reason why you're not able to do the time they initially request, just let them know you're not available then but could do ___ or ___ and ask which is better for them.
Typically a buyer will have a list of homes they're wanting to look at and we'll be setting up appointments to see several at once. Have them text/email you the list of houses they want to see, confirm the time that you're going to meet them, and tell them you'll let them know which house you can start at once you have the appointments confirmed.
When you're showing multiple homes, put all of the addresses on a map and then order them in the list to minimize the total driving time. Which end of the map you start first is usually best determined by where you're coming from, so that you can minimize driving time.

Unordered list with driving time of 1 hour and 16 minutes

Ordered list with driving time of 56 minutes
If you're showing multiple clients during the day, or have other things on your schedule that you're coordinating around, it's best to put everything for that day on the Google Maps list and then order the list to minimize your total driving time.
In the example below, I'm showing Client #1 a home in Powder Springs at 9:30am and then I'm coordinating appointments to show Client #2 three homes in the Acworth/Woodstock area at 2pm.


Routing for the 4 houses, starting in Powder Springs with Client #1 and then starting with the closest to Powder Springs for Client #2
In this scenario, I would figure out a convenient place for me to work from between those appointments (Atlanta Communities office, coffee shop, home, etc.) and then order them so that I'm driving the most efficient route:


Once you have the order determined, you can schedule the actual showing appointments for each house. Depending on the client and their interest in the house, you could spend anywhere from 10-20 minutes at a house up to an hour or so. A good rule of thumb is that each house will take about 20-30 minutes on average. When possible, book 1-hour appointment windows to give you some flexibility in case the client runs late or takes longer than usual at a showing.
<aside> 🕒 Sometimes the listing agent will have the ShowingTime system set to only allow 30-minute or even 15-minute appointment windows. In that case, you'll just have to book it starting at your appointment time with the client and do your best to be finished with the appointment on-time.
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So for Client #1, I would try to schedule a 9:30-10:30am appointment at 4845 Brown Leaf Drive in Powder Springs. I'd likely be done with the appointment around 10 or 10:15am and head to the office to work until my next appointments.