The date was released at Apple's live event in California.
The first iOS 11 beta was released in June at Apple's WWDC keynote. Following a total of ten public betas, Apple has now set an official date of 12 September for its general release.
This bucks the trend somewhat, as Apple usually makes the latest version of its OS immediately available for download when it reveals the latest generation of iPhone - in this case, the iPhone X. Instead, it will arrive a full week after the phone's debut.
As with all iOS updates, iOS 11 will be freely available to Apple customers with compatible devices. This time around, the minimum supported devices are: iPhone 5s and upwards, iPad Mini 2 and upwards, iPad 5 and upwards, and all iPad Air and iPad Pro models.
iOS 11 features
iOS 11 brings with it a number of new features, including both surface-level cosmetic tweaks and seriously meaty feature upgrades. There's a slew up updates, but here are the biggest things that Apple is introducing with its latest iOS version.
Apple has improved its signature AI voice assistant for 2017's range of devices, making its male and female voices more expressive and natural, enabling them to adjust intonation and pitch as well as emphasis and tempo.
It's now able to translate English words and phrases into Chinese, French, German, Italian and Spanish, and can offer more personalisation based on use of Apple's Safari, News, Messaging and Mail apps, suggesting topics you search for on Safari when you're typing an email, for instance.
A big new feature for iOS 11 is the inclusion of augmented reality, with iPad and iPhone developers encouraged to use their built-in camera and motion sensors with the new ARKit to layer virtual elements on top of the real world for a different take on apps and games.
Apple's upgraded Portrait Mode to take pictures with optical image stabilisation, True Tone flash and HDR, to make them better-looking than ever. While Memory movies can now play in both landscape and portrait modes, Apple is conscious of your storage space, so uses High-Efficiency Image File Format to halve the size of every photo you take on iPhone 7 and 7 Plus (and presumably on the iPhone 8, too).
Apple Pay person-to-person payments
Apple Pay gets ever more convenient with iOS 11, now allowing you to not only pay over the counter with contactless technology, but pay friends simply by sending an iPhone-to-iPhone text using Messages. For the first time, Apple is also allowing users to authorise payments using facial recognition, using its new FaceID technology. If voice is more your bag, you can use Siri to pay someone with the debit or credit cards you have stored in Wallet. Recipients can transfer the money from their Apple Pay Cash account into their bank account, or use it to buy things using Apple Pay.
Disable Touch ID
Apple has also added a feature that allows users to bypass the Touch ID fingerprint scanner in order to make a call to the emergency services. By tapping the Touch ID button five times on a compatible iPhone, iOS 11 will bring up the option to dial emergency services without the need to enter a password to make the call.
The idea is the new feature is to ensure that iPhones can still be useful in situations where the user might be in danger or if they are having difficulty dialling the emergency services, or if they are unconscious and someone else needs to use their smartphone to make a emergency call.
Furthermore, the five rapid taps disable Touch ID and revert into requiring a password to be tapped in to the handset in order to activate it; a useful feature in situations where the user may be forced to unlock their phone using Touch ID, for example by authorities seeking to make people unlock their phones with their fingerprint in order to access their data.
The fingerprint scanner will then be disabled until the user puts in their password which will then switch Touch ID back on. Essentially, the additional feature adds another privacy option into the security suite of iOS 11.