The Walking Dead Volume 28

Received my copy of the The Walking Dead trade paper back, Volume 27: The Whisperer War, in the mail a few days back.  Haven’t read it but have read all them up to that.  Got thinking when will be the next one be out.  Which will be volume 28.  There is not official tittle or release date yet.  Took a look at when past volumes came out.  Most years there are two trades a year.   So my guess will be some time in September (2017).  Looked on a few online stores.  They are saying the 19th.  That could be a place holder.  Will be back when there is more info to share.