You actually bring up a good point. I would agree that it somehow creates the illusion of having something continuing and never really ending, whereas if you have “Summer 2021”, it has a definite beginning and end, and that’s it, you’ve completed it, congratulations. But considering this, I feel like having for example “Read Every Day Challenge - September to November” in the title creates much of the same. Even if not numbered, it’s somewhat “numbered” with words if that makes any sense
. If we go with this route, I think either Autumn or Fall 2021 would be a much better choice.
So that leaves me with the final thought: we can bend a bit the seasons, and leave it at that.
As for the polls, I chose September-December just for the sake of making it easier when the new year comes:
Winter: January, February, March
Spring: April, May, June
Summer: July, August, September
Autumn: October, November, December
Personally I don’t consider December being Autumn, or mid September being Summer, but it’s the closest to the actual seasons, it would just start 10 days after, ish.
We would have both November and December as rest months, so we could maybe do a small “spin off” thread in between? 
And lastly, I wonder if we do have indeed southern hemisphere participants. I would bet the vast majority of us are from northern hemisphere countries, and it’s probably the most convenient overall, but I’m not sure how we could name it while avoiding numbering it (Q1, Q2, etc, wouldn’t work either, or would it?
).
Ultimately however, I really don’t mind how we name it, the important part is actually doing the reading
,
I mean, I don’t even know the schedule of my exams yet, so I have no idea when I’ll have time to read



From what I’ve observed during this thread, some were reading even if their daily life were busy, some started a bit later when they were not as busy anymore.
)
I didn’t assume that you’re planning to read Genji Monogatari as your first book, you know!

The stakes and issues they deal with in high school vs. elementary school would also be on a different/higher level, I would assume, so maybe they felt like the high school age would make for more interesting watching for the target audience? Not sure, it will be interesting what other differences there are, and whether the light novel “feels” different to the anime
And like you said, being able to see character’s growth also sounds more exciting 


I’m going to count it as an official start to the challenge for myself, and start reading everyday again!