Apple

A report says T-Mobile is blocking employees from taking Sept. 20 off because that's when the latest iPhone may go on sale. (Justin Sullivan / Getty Images / April 23, 2013)

T-Mobile is reportedly blocking employees from taking Sept. 20 off, a move that could indicate when the newest iPhone models will go on sale.

For weeks, reports have said that Apple will formally unveil the iPhone 5S and the low-cost iPhone 5C on Sept. 10. but normally, Apple doesn't begin selling an iPhone model on the same day it is unveiled.

In the past, the Cupertino tech giant typically announces the phone, begins preselling it and then finally starts delivering the device and selling it in stores. The release date is usually on a Friday.

PHOTOS: Biggest tech flops of 2013 -- so far

According to TmoNews, a news website that covers T-Mobile, the Seattle-based carrier is blocking employees from taking off Friday, Sept. 20, through Sunday, Sept. 22. Although TmoNews says this could still change, the move seems to suggest T-Mobile is preparing for some heavy business that weekend, which would likely happen if new iPhones went on sale.

Apple could not be reached for comment on the release date, but Sept. 20 makes sense a lot of sense.

If Apple introduces the iPhone 5S and 5C on Tuesday, Sept. 10, it could kick off preorders on Friday, Sept. 13, and then deliver devices and put them on sale in stores one week later.

Apple is expected to introduce the iPhone 5S, which would look like its predecessor but receive some internal upgrades and be available in a new gold color option. The company is also rumored to be planning to unveil the iPhone 5C, a lower-cost, plastic-case version of the iPhone 5S.

ALSO:

Universe crumbles as Oxford dictionary adds 'selfie,' 'twerk'

Another Google bombshell: Android exec Hugo Barra resigns

Google co-founder Sergey Brin reportedly splits from wife Anne Wojcicki