Depends on what part of training the wedding falls. There's not much flexibility in the classroom time (first 4-5 days). Sims are bid on depending on your class seniority. Maybe talk to guys more senior than you and tell them your situation. Once your in OE, training scheduling will do their best to work with you and are usually accommodating. After OE they will build you a line for the remainder of the month. They are accommodating as well. Once the next month hits and your under PBS again all bets are off.