Hey everyone, I decided to do both myself and all of you a favor by reading the novel and creating a timeline of the events. I put it together in Paint, but it's all done with heart. Here’s what I came up with:
As you can see, chapters 1–12 don’t include any specific timestamps. Instead, they offer vague details like 'A completely ordinary day,' 'Just a little past 7:00 a.m. on a weekday,' 'A sunny afternoon on a holiday,' 'A usual day, a long afternoon at 10 PM,' and so on. Given this, I’d say chapters 1–12 most likely took place during year 2, but that’s just a guess.
About the chapter... I’ve got nothing.
Thanks for the chapter!
Edit:
@GennArc pointed out that in chapter 12, Seki/Kan refers to Yuu as "senpai." So, it’s likely that chapters 1–12 took place after April of year 2.