Apple Inc. (NASDAQ:AAPL) is gearing up to launch two iPhone 6 models, 4.7-inch and 5.5-inch, later this year. While many reports suggest that the next iPhone will be launched in September, there have been persistent rumors that the 4.7-inch version will hit the markets in August, followed by the 5.5-inch model in September. But the August release seems unlikely.

iPhone 6

Apple restricts employees from taking vacations in September

When Apple Inc. (NASDAQ:AAPL) plans to launch a new device like the next-gen iPhone, it restricts vacation time for its retail staff. A report by German site iFun says that the German Apple Store staff have been restricted from taking any vacation in September. There is no such ban in August. The tech giant usually unveils its new iPhone models in September. But there are still speculations that the phablet version of iPhone 6 may be delayed due to battery problems, and manufacturing issues.

Anyway, the restriction in September indicates that Apple Inc. (NASDAQ:AAPL) is set to launch the iPhone 6 in September. Moreover, a split launch for the two versions doesn’t make sense for a company like Apple for a variety of reasons. There will be logistical hassles upon launch. So, if there were two launch dates for different versions, there have been vacation blackouts for two months rather than one, says Ben Lovejoy of 9to5Mac.

Apple unlikely to launch iPhone 6 in two phases

Moreover, a two-phase launch will provide rivals with data on relative popularity of the two versions. Apple Inc. (NASDAQ:AAPL) never reports iPhone sales figures for various models. Over the past few months, we have seen various mockups and renders of the rumored iPhone 6 design. All of them point to slim form factor, rounded edges and an iPod Touch-like design. Apple’ new smartphone is expected to sport a scratch-resistant sapphire display, NFC, metal casing, TouchID fingerprint sensor, an 8MP camera, an upgraded A8 processor and iOS 8.

Apple Inc. (NASDAQ:AAPL) shares inched up 0.22% to $595.06 at 9:48 AM EDT on Wednesday.