Yeah, you could've started your attack one turn earlier (since I received your cancellation notice turn...15 I believe).
The cancellation period is basically how much notice the opposing nation gets of the attack before hand (so NAP-0 means attack goes along with the notice, NAP-1 means the turn after they receive the message before the attack begins, etc.). So if they
receive the cancellation message on turn 22, you can attack on turn 24. If you sent it out on turn 24 (so they'd receive it on turn 23), then you can attack on turn 25 (i.e. battles can break out, and you can send the orders in with turn 24). Dat make sense?
