By Josh Ong

Published: 08:00 PM EST (05:00 PM PST)

AT&T employees have allegedly been prohibited from taking vacation during the last two weeks of September, a move that may signal the timing of the next iPhone release, according to an unconfirmed report.

An tipster claiming to be an AT&T employee told Gizmodo on Friday that Apple's launch of the next iPhone is expected to occur at the end of September. However, the publication has listed the report as "unconfirmed," joking that readers should take the rumor with a "pint" of salt because it concerns Apple.

"I'm an att employee and my boss just announced that vacation requests for the end of september will be denied due to an "event blackout". Historically the only time they've done this was for an iphone release. So we're looking at the last two weeks of september," the tipster wrote in an email.

Those dates do align with recent reports that have narrowed down September as Apple's supposed timeframe for the next-generation handset. A separate alleged source within AT&T claimed earlier this week the wireless operator has warned employees to expect increased foot traffic in September ahead of a launch during the middle of the month.

Another report earlier this week also put forth the second week of September as the launch window for the iPhone 5, adding that the initial shipment is expected to total four million units. Bloomberg reported in June that the iPhone 5 is due out in September, though it did not specifically state when in the month the device would arrive.

During a quarterly earnings call last week, Apple itself indicated that it will undergo a "future product transition" during the September quarter, prompting speculation that the mystery product is in fact the iPhone 5.

Apple's next smartphone is expected to receive the A5 processor that made its debut in the iPad 2, a dual-mode baseband chip from Qualcomm that would support both GSM and CDMA networks, and an 8-megapixel camera.