I'm assuming you are a C4C. Summer sessions are used for military and leadership training. After C4C year they may have 1 session on leave, 1 for ESET (survival training) and one for airmanship: jump, soaring or space. Some cadets may need to skip airmanship to make up a class and some voluntarily give up leave to take a class over the summer. ICs sometimes do this to relieve a packed schedule during season.
Sometime after winter break your cadet will put in a request for the summer sessions. He/she will rank their order of priority, how much they want a certain session for leave, jump vs soaring, etc. If it is important for you cadet to be off a certain summer session, for example, they could put that as a '10' with a better chance to get it off, though certainly not guaranteed. I believe class rank matters as those with higher class rank have a better chance to get their first choices. If I recall last year we found out around spring break what the summer schedule is. Clearly that is late for you to be planning wedding date. You will likely just have to set a date and hope he can get that session for leave. The summer sessions run 7 days a week, so don't plan on having a weekend off.
Another alternative is before graduation. There is an opportunity for a 96 hour pass after finals and prior to graduation week. Not sure the exact timing of that but your cadet could probably find that out now. Of course, this is assuming that he/she is not restricted in any way.
Worst case scenario: One of our classmates missed his brother's high school graduation and his family made a full sized likeness of their cadet and took him to all the events so he could be in the pictures. 'when life hands you lemons, make lemonade'
Congratulations on the wedding!!
