God, it has been so long.
The Gettysburg '64/'65 Time Record Chart starts with "At Start", then has the 6 AM turn.
Can the players move their units in an "AT Start" turn, or can they 1st move units in the 6 AM turn?
My recollection (and it has been a while for me too) was the At Start was just for placement and the 6 am was the actual first turn. I think that is how I played it.