A-Day is not a parent participation event. It is basically the graduation parade in reverse where instead of the graduating class marching out of the company, the incoming 4th class march in. After the parade they may have optional social events scheduled, but nothing formal that would require that a guest should wear a uniform. Back in the dark ages when I was a new fourth class cadet, I was just told there was a parade today and which afterwards we would no longer be considered new cadets. Parents were not invited or informed it just happened at a time sometime in the middle of the week. I remember spending most of the parade trying to figure out how I was going to get the laundry, I was head laundry carrier that week, that was incorrectly delivered to A1.