Now we are in the past :p
I think this timeline post will help clear things up for you. I know because it helped me big time!
4 http://alliandoalice.tumblr.com/post/129187300952/timeline-19-days
It's probably their past when they were in middle school (Although they don't really look like middle schoolers to me xD)
especially in this last chapter 129. looked like the author drew them as their college version instead by mistake haha
wait, if Jian Yi is in high school while zhan zhengxi is in university, then how come they are going to the same school along with he tian? does that mean right now is a moment in the past?