Apple's  (AAPL) - Get Report  iPhone 8 has been hyped up so much that CEO Tim Cook actually blamed the media coverage of the yet-to-be released phone for the disappointing iPhone sales in the second quarter. 

According to Cook, customers are getting so excited about the 10th-anniversary edition of the iPhone expected later this year that they're holding out for it instead of buying an older model. 

However, reports and comments from suppliers suggest Apple may not be able to keep its tradition of releasing the newest iPhone model in mid-September due to supply constraints for the OLED display panel and other components. The release date could be pushed back to November or even December, which could have significant implications for its revenue in upcoming quarters. 

The key number to listen out for is Apple's forecast for the fourth quarter, which ends in September. If Apple is on track to release the iPhone in September, then its forecast for the fourth quarter will be in line or higher than expected. But if Apple is anticipating releasing the iPhone in November or December in the 2018 first quarter, then the 2017 fourth quarter forecast will be lower than expected.

For the fourth quarter ended in September, analysts are currently expecting Apple to forecast selling 46.2 million iPhones. 

Jackdaw Research chief analyst Jan Dawson said he is wary of reports that the iPhone 8 will be delayed. "It's entirely possible we will see delays, but it's really impossible to know for sure at this point," he said. While a big delay would obviously hurt sales for the December quarter, it's not worth speculating at this point since that remains unclear, he added.

However, Dawson agreed that Apple's guidance is the best figure to look at for a hint as to where the company is in its production timeline of the iPhone 8. "It will give us a small sense of what they're expecting in the September quarter, which traditionally includes the first 10 days or so of iPhone sales," he said. "If there are supply problems, I'd expect that guidance to be a little lower than usual." 

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