The iPhone 5S and budget iPhone 5C are widely rumored to debut on Sept. 10 and it now seems that iOS 7 may launch on the same date.

While Apple has yet to confirm anything, numerous rumors, leaks and speculations have tried to paint a picture of what to expect from Apple's new iPhones. The Sept. 10 date falls in line with the company's previous launch schedules and Apple reportedly plans to introduce both the new hardware and software on the same day.

The company behind Siri, Nuance, reportedly sent out an email on Monday, Aug. 26, telling developers that the iOS 7 will launch on Sept. 10.

"Dear NDEV Developer,

As you are probably aware, iOS 7 GA will be released on September 10th. The NDEV Program has pre-qualified that SpeechKit 1.4.5 works properly on iOS 7, but we encourage you to conduct your own testing to ensure that when the upgrade happens, your Nuance speech services continue to work seamlessly," reads the email from the NDEV Mobile Team, as published by Owened.

Nuance has had a very close relationship with Apple in the past, which only makes this information seem as credible as it gets outside of the actual media event invitation from Apple. Given Nuance's involvement with Apple, it would make sense for the company to know the iOS 7 release date before others. Still, it's no guarantee that this purported email is accurate so do take things with a grain of salt, just to be on the safe side.

From a historical point of view, this information is not farfetched. Apple has previously announced its new iOS version on its iPhone announcement day and released the Gold Master within a few hours. Apps built into the new SDK have for years been accepted into the store ahead of the public release.

In other words, if Apple does indeed intend to release iOS 7 to the public on Sept. 10, the company would most likely make an announcement and make the Gold Master build available to developers very soon.

One possibility is that Nuance may have actually referred to the GM becoming available on Sept. 10, but it's unlikely that the company would confuse things like that. The email has since disappeared from Nuance's servers but if it proves to be accurate, we'll be hearing more soon enough. Stay tuned.