Apple today announced it will release Sierra, this year's edition of the Mac's operating system, on Sept. 20.
The date was posted on Apple's website, but as with last year's El Capitan delivery date, the news did not rate a mention during the two-hour introduction of the new iPhone 7.
Sierra will be Apple's first under the "macOS" label introduced in June to dispense with the older "OS X" and put the Mac operating system moniker on par with others, such as iOS and watchOS.
The Sept. 20 Sierra release date is 10 days earlier on the calendar than 2015's El Capitan, and three weeks sooner than Computerworld's errant forecast using last year's schedule and this year's beta cadence.
Also on Wednesday, Apple issued the first Sierra "gold master" (GM) candidate to registered developers. Apple usually runs through several GM candidates as it stamps out as many bugs as possible before sending the software into the world.
If Apple follows last year's practice it will shortly ship the same GM candidate to customers who have previewed Sierra through the public beta program.
According to Sierra's system requirements, the edition will run on most, but not all, Macs now running its predecessor, El Capitan: MacBooks and iMacs from late 2009 on; MacBook Pros, Mac Minis and Mac Pros from mid-2010; and MacBook Airs from late 2010 forward.
macOS Sierra will be a free upgrade available from the Mac App Store.