t depends on which stage of the project your team is working on. Analysts/interns are more occupied during the initial month of the project as there will be a lot of market research to do. You might have to work round the clock occasionally but it is not as bad as investment bankers. In the mid part of the project, you can expect the normal business working hours as you will do more detailed research in less amount, such as risk analysis and building profit models. When it comes to the end of the project, the managers are busier coming up with strategies, so it is more chill for the interns. Usually, interns are not involved in the final presentation of strategy to clients.
Per the above, it can vary a lot but as you become more senior, its harder and harder to maintain normal work hours (whatever that means!). Depending on whether you're answering transactional data requests or staffed on a project it can vary quite a bit. When staffed to projects at client site, I often worked 9am-midnight, just like the consultants. If I was in my home office working on smaller projects or transactional data requests, I often went home at 6:30 or 7.