Oct. 10 has now come and gone. That date was only notable because there was buzz that Apple (NASDAQ:AAPL) was to send out official press invites to its iPad Mini unveiling. That speculation had stemmed from a relatively questionable source, a "major Apple investor," who told Fortune's Apple 2.0 that invites would be going out on that date.

Alas, that rumor has fizzled. Not to worry, my Foolish friends, for another rumor has now emerged on when iPad Mini day may at long last roll around. This time, though, it's coming out of AllThingsD, an outlet that boasts a very solid track record when it comes to iRumblings. The report pegs Oct. 23 as the date of the unveiling, which is Mole Day for you chemistry buffs out there (this year's theme is Molar Eclipse).

Chances are that the event will be lower-key than the iPhonepalooza last month, where Apple even hired the Foo Fighters to perform at the iPhone unveiling. The iPad maker may simply host the invite-only event in its Town Hall Auditorium on its campus headquarters.

That date would be just three days before Microsoft (NASDAQ:MSFT) launches its own Surface tablet alongside Windows 8, so an iPad Mini event could potentially rain on the software giant's tablet parade. Surface isn't the only tablet that will feel the heat, as Amazon.com's (NASDAQ:AMZN) Kindle Fire HD and Google's (NASDAQ:GOOGL) Nexus 7 have a lot to lose at the prospect of an iPad Mini entering the 7-inch tablet market. Apple's even reportedly ordered 10 million of these things for the holidays, double the Kindle Fire HD units that Amazon's targeting.

We're about halfway through October now, with no official peep out of Apple as to the device's existence, let alone any invites. Investors are widely expecting the device to be announced this month, and anything less would be a disappointment.

Evan Niu, CFA, has no positions in the stocks mentioned above. The Motley Fool has no positions in the stocks mentioned above. Motley Fool newsletter services recommend Costco Wholesale. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.If you have questions about this post or the Fool’s blog network, click here for information.