A few iPhone users have discovered that saying July 27 2014 to Siri will render an interesting answer. If you ask Siri "What is July 27" or "What is July 27, 2014" her response will be "It's Sunday, 27 July 2014 (Opening Gates of Hades)." This hasn't happened on all iPhones, but several people across the world have confirmed the strange message's appearance in the cyber assistant's interface.
It is uncertain why Siri is giving this response, although Cult of Mac have said it's all down to a glitch in the iPhone's Wolfram Alpha configuration, which directs Siri to give responses. Last month it was reported that if questioning Siri about political views, she'll display a Wikipedia page for former Republican Congressman Ron Paul. As with Siri's apocalyptic predictions, the Ron Paul-related message only appears for certain users.