Tracy, that is a very good question you ask. In my opinion, I believe it is the predominant goal of every Realtor who lists a home for sale to actually get the home "sold" so they can be compensated, since most real estate agents are only paid once a property is sold and closed. That being said, it only follows that most real estate agents educate homeowners on the importance of making their home showing schedule as flexible as possible. I do not think the problem lies with a lack of education to the homeowner on the part of the real estate professional. More likely the issue lies with the homeowner who may not fully understand how significantly an inflexible showing schedule will impact the ability to sell their home. This issue will usually correct itself when the home has not sold.
To more directly answer your question "Do you work around these specific times or do you just not show the home?", I will certainly make my buyer customer aware of that the home is available since I want to be sure that the buyer is fully aware of all listings on the market that meet their criteria, and I will leave it up to the buyer to determine if they still want to preview the home. From my experience, unless the home is a rare gem, there are too many other homes available for the buyer to choose from and they usually do before they end up going back through a list of homes with inflexible showing times.