Just like they would expect their time to be respected, so they should respect yours. We work from home all day so many "day" appointments must be done in the evenings.
I recently was trying to arrange an interview with a referred potential client. When I said I wasn't available on a particular evening she became snotty about the limited time frame I had for my interviews. Big red flag there, and now (to her) that spot has been taken. As desperate as I am to fill this spot, I am not looking for a headache client.