Charts are super-well implemented overall, but I think a minor tweak to range would help as follows:
For both week and month, make the endpoint of the graph yesterday, and not today.
Part of the value of these charts for those ranges (week/month) is the ability to plot trends - like the recent huge upswing in traffic.
It's a bit disconcerting (for several new users I've talked to), to see today always as a downswing (even though it's not - it's only 1pm and it's barely half over - of course your stats aren't up to yesterday's levels!).
I believe making the cutoff for those two chart ranges last night at midnight (ie. 3/3/2016) would make the plot trend inequivocally clear, and users who want to see the last 24 hours can always click on "Today".