On September 9, 2015, Apple announced the 4th generation Apple TV, to ship in October 2015. It is the first major update to the platform since the release of the 2nd generation Apple TV on September 1, 2010. Tim Cook took the stage and said "The future of TV is apps". He also stated that the Apple TV needed a modern OS. While matching the form factor of the 2nd and 3rd generation models, it is significantly taller. The 4th generation Apple TV features a new touch remote allowing swipe-to-select functionality instead of the old remote's arrow button, and integrated Siri support with a built-in microphone and an accelerometer (IMU). The Siri button on the remote allows several functions, including searching across providers for content, accessing additional metadata and video / audio controls.

Answer this question based on the passage: when did apple tv 4th generation come out? Let's have some stream of consciousness first.
This is the relevant information: On September 9, 2015, Apple announced the 4th generation Apple TV, to ship in October 2015. So, the answer is October 2015.