They have academic calendars for next few years. Here is 2017-18 https://www.provost.umd.edu/calendar/17.cfm Looks like May 20 and 21. Here is the commencement info page http://commencement.umd.edu. Unfortunately, the Marriott doesn’t book that far out and it really is like calling Disney for Princess breakfast tickets…you must call exactly the moment they open up the rooms, because by 10 a.m. they are sold out… The new hotel isn’t taking any reservations yet, and I haven’t seen any estimated opening dates other than Spring 2017…