Before answering scheduling questions, it's important to be clear on the interviewer's expectations. If you haven't had a chance to clarify their scheduling needs, now would be the perfect time to ask. If they expect you to work 12 hour days, it would be important for you to know that before responding with, 'Absolutely! No problem!' You want to be sure that you can meet their expectations. If it turns out their schedule expectations won't work for you, think about what you CAN offer and see if you can meet in the middle. It's much better to discuss these things in an interview than to commit to a schedule that won't work for you.