If you're talking about the "announcement" where Roger posts the cover art to the Intrada forum to reveal what their next title will be, you can look at their past history to see how many days before each Release Day Roger tells us what we're getting
Jan 12 - Psycho III {revealed 11 days prior on Friday Jan 1 @ 7:14pm}
Jan 26 - none
Feb 9 - none
Feb 23 - Flight of the Phoenix {revealed 7 days prior on Tuesday Feb 16 @ 3:39pm}
Mar 9 - Legal Eagles {revealed 10 days prior on Saturday Feb 27 @ 2:38pm}
Mar 23 - Face of a Fugitive {revealed 24 days prior on Saturday Feb 27 @ 2:38pm}
Apr 6 - Company Business {revealed 5 days prior on Thursday Apr 1 @ 3:25pm}
Apr 20 - none
May 4 - Rio Conchos {revealed 5 days prior on Thursday Apr 29 @ 12:57pm}
May 18 - Deepstar 6 {revealed 4 days prior on Friday May 14 @ 3:43pm}
Jun 1 - Shamus {revealed 6 days prior on Wednesday May 26 @ 11:21am}
Jun 15 - The Public Eye {revealed 5 days prior on Thursday Jun 10 @ 2:58pm}
Jun 29 - Call of the Wild {revealed 5 days prior on Thursday Jun 24 @ 5:49pm}
Jul 13 - Extreme Prejudice {revealed 5 days prior on Thursday Jul 8 @ 4:41pm}
Jul 27 - Sleepy Hollow {revealed 5 days prior on Thursday Jul 22 @ 10:58am}
Aug 10 - The Eiger Sanction {revealed 5 days prior on Thursday August 5 @ 1:21pm}
Aug 24 - Julius Caesar {revealed 4 days prior on Friday August 20 @ 6:33pm}
Sep 7 - none
Sep 21 - none
Oct 5 - To Kill A Mockingbird / Walk On The Wild Side {revealed ??? days prior}
Looks like he's most likely to do it the Thursday beforehand, so that's 1 week from today
If you're talking about the actual Announcement where the store page goes live with Doug's write-up, the track list, the samples, and you can actually order it, that always happens on Monday evening between 5:30 pm ish and 8:00pm ish, and in this case that will happen the evening of Monday, October 4th.