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The reputation by month page(s) on Mathematica appear to be wrong. Presently it looks like this:
According to the hover-over that is "2016-08-01 to today."
The quarter page, which is "2016-07-01 to today":
Observe that users Szabolcs, kglr, Simon Woods, Bob Halon, Jens, Edmund, and halirutan have the same reputation on both pages. This would indicate that these users gained no reputation for the entire month of July, but a review of the reputation pages will demonstrate that this is false.