[asdff]

The timing thing probably has to do with when people get off work or aren't prepping meals.

[sudosysgen]

I had this intuition too, but time zones, breaks, procrastination, variation in meal prep + time zones very likely cancel it out.

It's not simply the amplitude changing, but the sign of comments too - it can go from neutral to upvoted to downvoted and back, so simple patterns in activity can't quite explain it.