The event was touted in those invitations, as well as on Apple's website, with the line, "Hey Siri, give us a hint," a tag that may prove true rumors that the Cupertino, Calif. company will introduce a revamped Apple TV with voice control along with the usual annual slate of new iPhones.
Siri is Apple's virtual assistant that as of today is available only on iOS.
Also on Thursday, Apple said it would live-stream the event -- and for the first time, the webcast will be available from a stock Windows browser.
Previously, BuzzFeed's John Paczkowski, who has correctly pegged several years' worth of Apple event dates, tapped Sept. 9 as 2015's iPhone roll-out. The date fit with earlier iPhone cycles, except that it appeared to be pushed back one day from the usual Tuesday to take into account the Sept. 7 Labor Day holiday in the U.S. Asking employees to prep for the event on Monday, and more importantly, getting invited to travel on an off day, may have prompted Apple to pick Wednesday instead.
The presentation will start at 10 a.m. PT, 1 p.m. ET, and will be held at San Francisco's Bill Graham Civic Auditorium, a venue named for the rock 'n' roll promoter and impresario who produced shows featuring bands from Big Brother and the Holding Company to the Grateful Dead.
As it has for several cycles, Apple will webcast the event via Safari on iOS and OS X, and to Apple TVs. In years past, Apple has left Windows users out of the loop, catering instead to its own device owners. This year, however, those who have upgraded to Microsoft's Windows 10 can use the Edge browser to view the live stream.
Unless Apple drastically departs from its standard cadence, it will unveil iPhones tagged with an "S" -- as in iPhone 6S and iPhone 6S Plus -- packaged in the same designs as last year's iPhone 6 and 6 Plus. These off years often come with lowered expectations and a less frantic buzz than when the faithful anticipate new form factors.
They can also bring a certain amount of doom and gloom, said Carolina Milanesi, chief of research and head of U.S. business for Kantar WorldPanel Comtech. Added to that is skepticism by some that Apple will be able to match the success of last year's larger-screen smartphones.
There is some truth to the thought that the speculation machine may be running at half throttle, Milanesi argued, but Apple is not alone. "Smartphones are just not as sexy as they used to be," she said. "I felt the same way two weeks [about Samsung when it introduced the Galaxy Note 5 and Galaxy S6 Edge Plus.] Here is another one."
But Milanesi cautioned against both complacency and writing an iPhone eulogy for 2015. "The numbers still look good [for the iPhone]. There are a lot of people who still have the older models," Milanesi said, giving a nod to survey data that Kantar will release next week.
"For me, what I'm eager to see is how many will pick up the lower-priced 6 Plus," Milanesi continued, referring to Apple's practice of retaining last year's model or models at discounted prices. "That's the long tail of what you'll see as people with a 4S or 5 upgrade."
And it's a bad idea to bet against Apple's promotional machine in an off-year when expectations may be lower, or even very low because of iPhone 6 and 6 Plus sales. "That's the time where Apple has an advantage, when we're not expecting another rabbit out of the hat," Milanesi said.
At the least, Apple will also take time to talk up iOS 9 and announce its imminent availability -- likely on Sept. 16 -- and highlight Apple Watch, perhaps with third-party developers strutting native apps crafted with the new SDK (software development kit) for watchOS 2. There is also a chance that Apple will identify the release date for OS X El Capitan, the Mac upgrade that has been on an accelerated schedule.
The presentation will be viewable from Apple's website.