After an animator's resume had leaked the plans for the new Monogatari anime, it was confirmed for fall during Shaft's celebration of the summer Tanabata festival
While there hasn't been much in the way of promotional work for Owarimonogatari, Japanese blogs are listing that the show will take Charlotte's midnight slot on Tokyo MX starting October 3rd, followed by TV Aichi, Television Saitama and MBS on the 6th.
終物語 2015年10月よりTVアニメ化決定！！！！ 書泉ブックタワーより pic.twitter.com/CGiPJq5HQX— マウノウ@7/7 ガハラ祭 (@maunou777) July 7, 2015
Owarimonogatari ("End Story"), comprised of three volumes, is the twelfth part of the Monogatari series. The fifteenth, sixteenth, and seventeenth books overall, they contain the stories Ougi Formula, Sodachi Riddle, Sodachi Lost, Shinobu Mail, Mayoi Hell, Hitagi Rendezvous, and Ougi Dark.