In theory there's no way to know exactly when the announcement...

In theory there's no way to know exactly when the announcement will come out except of course if things are stretched to the obligatory maximum time allowed by ASX which is prior to market open on Monday 20th ( unless the stock goes into suspension for not reporting). But is the ASX a level playing field ? . All I know from experience of watching other stocks is that as we approach a pre-open, and an announcement is forthcoming, I have often seen an obscene rush by some buyers who fall over themselves to get in the queue prior the announcement. Now maybe its coincidental, maybe they have a premonition, maybe ???
I'm just a simple trader, if I see buyers bidding strongly before an anticipated announcement, I have a pretty good inclination as to how things will go post-announcement. It tends to be right more often than not right.