It seems like a dumb question – are you on a date with the person you're interested in or is it something else? But as the rules of courtship degrade, so do the parameters of what constitutes a date, so it's important to know beforehand what you should expect and what's expected of you. Here is what a date isn't: He calls up asking to meet somewhere, then when you arrive, he's hanging out with his buddies. A last-minute call asking if you're doing anything that night? Potentially, it could be a date, but it sounds more like a "hangout" or booty call – or perhaps his original plans fell through! Being invited to his house without the promise of a night of dinner and perhaps a movie in doesn't mean it's a date.
More than just you and him on the "date"? Sorry, not a date. And if a co-worker or client invites you out under the guise of talking business, take that at face value and don't assume it's a date – you could damage your professional relationship. A date happens when one person contacts another person to make advance arrangements to go somewhere. And by "advance," we don't mean an hour before things happen. Unless agreed upon in advance, a date is a one-on-one situation that doesn't involve his college buddies or your sorority sisters. Double dates with mutual friends are a great way to take the heat off a first date, however. Dates exist so that you can explore whether any romantic feelings may exist between the two of you; there is no such expectation when the event is a non-date.