" Fans have speculated Hyojoon's discharge to be on the 27th of September in 2015, a mysterious date given in Jiyeon's solo mini album that matches up with his mention of having 9 months left!"
I think this may very well be true! - There are a couple of photos I think that show Hyojoon and Jiyeon drawing what ended up being the inside of Jiyeon's Mini Album. (I could be wrong here but I can't find the photos either :/)