Unixmen reports that the release schedule for Ubuntu 11.10 "Oneiric Ocelot" operating system has been published on the Ubuntu wiki
June 2nd, 2011 - Alpha 1 releaseUbuntu 11.10 Oneiric Ocelot Release Schedule
June 30th, 2011 - Alpha 2 release
August 4th, 2011 - Alpha 3 release
September 1st, 2011 - Beta 1 release
September 22nd, 2011 - Beta 2 release
October 13th, 2011 - Final release of Ubuntu 11.10