Pretty sure the graphs in the tools section of VGC use week-ending method for month (I havent checkes every 5-week month but those that I have consitantly include weeks ending 1st/2nd/3rd within that same month, so I believe the week ending 2nd Jan 2021 will be counted in the January totals when you arrange by month)
However Trunkswd mentioned in another thread that for yearly totals it might be different as some past years have had weeks ending in early Jan counted toward previous year totals... Which if true is kinda odd.
I have the same confusion, I think that is what is going on, which makes it a bit tough to easily compare consoles, specially when they are really close.
What do you think about trying to divide the week by 7 and just multiplying by the days each month has for that week. It wouldn't be exact but it should be a bit closer to reality in all cases.
One down side of doing that is that it wouldn't match VGChartz values and it might make it a bit tougher for people to double check. In that case, trying to match VGChartz would be most appropiate (although tough when dealing with two different ways of sorting at the same time).
What do you recommend?