For Each one, scroll down to “Daily New Cases”
In Brazil and Mexico it is very strong.
In the US it is mild/medium.
In India and Russia, it is virtually non-existent.
My best guess is how much of the society changes habits on weekends (closed doctor offices, closed government agencies)? But does India and Russia really run 7 days a week?
My stab at it: Part of that may be labs might be closed or reduced capacity on weekends, and facilities to get tested and whatever is used to transport the samples. From what I know of Brazil and Mexico a lot of their culture stems from a christian/religious perspective which included respecting the holy days including at least the Sunday, but Saturday gets carried along. It is also time with family which is very important. It is hard to get things in such countries on weekends as many places are closed. In the US we have moved away from weekend closures, trading the christian traditions for consumerism and family time with adventure time (and consumerism). So we have moved more towards more things being open on weekends. Not so sure about India and Russia, but India is not know for christian roots, and for a while the USSR was not a friendly place for it, so I would suspect that they have other customs that don’t have the same week/weekend schedule.
With all these statistics you/we need to understand whether they’re reporting the date something happened or the date they received the report that something happened.
And for those of us using consumer websites, we have no idea how many intermediaries are involved in stirring the data before we see it.
Bottom line: IMO it’s all noise, no signal. Not much more can be said.