The point started out with his easy it could be to make a left crowned Sub. I just said you could turn the watch around as is but you would need to mount the dial 180° different to the movement in order that the indices show correctly with 12 at the top. The only proviso being that the mounts would have to be compatible. Doing the above means the dial stays the same but with case and movement at 180° to it.
As long as the date stays where the date window originally was, then it’s the correct orientation.
Now if you were to have the date at the opposite side to original, then it would indeed be upside down, but you would have to create a new dial then anyway, so having a new date wheel printed in the same 180° flip would hardly be an issue then.