haha all good, i'm just curious how it works. So why would you...

haha all good, i'm just curious how it works.

So why would you need to sell by Tuesday if settlement is Wednesday? I found on comsec it said if the sale amount is less than the buy amount, i.e. buy $10k and then sell for $8k, then the transaction on Wednesday is $-2k, which I get. But if it's a +ve amount the rules seem to be different.
Why wouldn't you be able to sell on the Wednesday, isn't that still within the T+2 period?