The unsafe part is the strangers in the home with no one to hear you if you scream etc. In reality the chances of there being an issue are close to nil but also are you willing to take the chance that this man and woman with a baby in tow aren't actually pedophiles. Also if only the mom and baby came then once she has narrowed down her choices she is likely to ask for a second visit so hubby can come and that would be at night so you end up giving up two visits.

Doing the visit at night gives you the chance to talk with the family, assess them too. They go away contact your references and make up their minds that way. In the grand scheme of things the numbers in care change so often that what is there today will be different when she starts anyways since assuming you have one leaving and need a new one to start so group dynamics will be different.

Also even when they do get to the ready to narrow it down and ask for a daytime visit it is done first thing in the morning as if they were going to work ie when kids just get there and everything is ready for the day. They stay for an hour and it is strictly freeplay with us mingling with the kids - everyone is usually on their best behaviour not tired, not hungry, not craving my attention. I do not do a circletime or "perform" in any way for the parent other than how I interact with the children. Make sure toys that normally cause issues have disappeared for that hour and then it is done and they are gone and you can start your day with only a limited delay. If you really must do an interview during daycare hours this is also the time to do it since the kids generally come happy to play.