Because showings are typically limited and good apartments go fast, be sure to have everyone who will be part of the decision making process present at all of the showings. That includes roommates and significant others. If someone, such as a parent, will have “veto authority,” they need to see all of the apartments with you, not just the one you finally decide on.
Not all apartments will be available to view on your schedule. Some will have very specific time frames (e.g. weekdays between 1-2 pm) or restrictions on when it can be shown (e.g. during business hours). Definitely expect to make Sunday afternoons available for apartment showings. Your broker will be able to make the arrangements to get you in, but you will need to make yourself available to see the apartments when they’re being shown.