HB I dont see that as an issue. In fact I would rather have the candidate ask questions in the interview. It shows you have an interest in the job. There may be some things - such as the work schedule that would not work for you. If you wait until the last interview only to find out that the job hours wont work, you have been wasting everyones time. Open communication is important. I have done a lot of interviews in my 30 yrs in HR and it would be irritating to get all the way through the interview process only to find that the job hours wouldnt work. I would rather have known that in the first interview - that is the purpose of the interview after all.
You can ask the question nicely as part of the conversation in the interview. It doesnt have to be a combative question. Smile and say, so can you give me a feeling for the scope of the job and what you are looking for? What the manager says in response to that, will give you an opening to “nicely” ask " this sounds interesting and its a job I would be interested in. What sorts of hours did you have in mind?
