I just figured I would mention this, incase anyone was interested in this information. The group goes to the carnival on February 14th(Valentines day) which is on a Wednesday according to Rosa. Valentines day last fell on a Wednesday in 2018, and before that Valentines day landed on a Wednesday in 2007. With the use of specific technologies like cell phones with nice cameras and such, I would assume that the former must be our date, meaning that volume 1 & 2 took place in 2017 fall and winter, and volume 3 takes place in early 2018.
It was just kind of interesting to me, so I figured I would mention it for future reference when we start making theories about the books..
From what I know: Volume 1 takes place late October and most of November 2017, Volume 2 takes place 2 weeks after Volume 1 placing it in December 2017, Volume 3 takes place during February and March 2018