They've pushed back class dates for important events, such as graduating college, etc. Don't think "a trip with friends" qualifies. Maybe you can lie and say you're going to a family wedding or something, but I wouldn't risk it. That being said, according to the class list there are currently 2 Terminal classes and 3 enroute classes in the beginning of May that would overlap with your dates, so it's possible you miss those completely anyway. If it were me I would just cancel my trip rather than try to push back the class date.