Apple will release the iOS 4 update today around 1 p.m. ET, 10 a.m. PT, according to claims from users citing calls to the company's sales and support desks.
As of 11:45 a.m. ET, the update, which Apple said earlier this month would be delivered today, was not yet available via iTunes. Apple updated iTunes to version 9.2 last week to make the software compatible with the new mobile OS.
Several iPhone owners on Apple's support forum claimed that they had been told by Apple support personnel that the iOS 4 update would launch at 10 a.m. PT. Apple is headquartered in Cupertino, Calif., in the Pacific Time zone.
Computerworld was not able to confirm the reported launch time; Apple's telephone lines were swamped with calls, with wait times that exceeded 30 minutes.
The timing would match what Apple did last year when it rolled out the then-new iPhone 3.0 on June 17 shortly after 1 p.m. ET.
Owners of 2008's iPhone 3G and second-generation iPod Touch, and 2009's 3GS and third-generation iPod Touch, will be able to download the free iOS 4 upgrade today. iOS 4 will not be available to users of the first-generation iPhone or iPod Touch, both which debuted in 2007.
Previously, Apple has dinged iPod Touch owners $10 for major operating system upgrades, but an accounting change last year now allows it to provide iOS free of charge.
Apple previewed iOS 4 -- formerly called iPhone 4 OS -- last March. Two weeks ago, Apple CEO Steve Jobs touted the operating system's new features, including multitasking, folders and a unified e-mail inbox.
The new iPhone 4, which will have iOS 4 pre-installed, is scheduled to go on sale Thursday, when Apple's retail stores open at 7 a.m.
Apple, AT&T, Best Buy and Apple's other U.S. retail partners quickly exhausted their pre-order inventories of iPhone 4s last week, when both Apple's and AT&T's ordering systems collapsed under the strain. Apple later apologized for the fiasco.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer or subscribe to Gregg's RSS feed . His e-mail address is firstname.lastname@example.org .
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This story, "iPhone OS 4 Upgrade Launches at 10 a.m. PT" was originally published by Computerworld.