Commissioning Week, Traditions, Folklore and Pranks
On June 10, 1854, nine years after the founding of the Academy, was the first formalized graduation. The sixth Superintendent of the Naval academy, Admiral David Dixon Porter, added parades, dances and athletics to the graduation week. In 1912, for the first time, graduates were commissioned on the same day as graduation. Then, in 1979, when changes were made in the Academic calendar that moved graduation to May, June Week was renamed "Commissioning Week." In 1966 graduation was moved to Navy-Marine Corps Memorial Stadium, where it is held today. Before 1966 it was held in the Chapel, Dahlgren Hall (1903 to 1965), and Halsey Field House (1957 to 1965.)
To the best of my knowledge the ceremony may have been held once since 1966 inside. Unless thunderstorms or lighting presents safety issue, parents will be glad to endure a little bad weather.
There is a story, apocrpahl or not, that one set if parents had two sons graduating the same year, the same day, one from the Naval Academy, and the other from West Point. They wondered whether the Academy would change their graduation date so both parents could attend both graduation ceremonies. Needless to say, it was not changed.