I don't know how the US does it but here they retroactively add cases to past days when they come in so by like Tuesdays the spike between Friday and Saturday evens out a bit. It might just be that the CDC just rolls over the weekend number to Monday instead so the spike stays. That's why it's better to look at a 7 day average. That's what's advised on all the coverage here.
That makes sense
I don't know how the US does it but here they retroactively add cases to past days when they come in so by like Tuesdays the spike between Friday and Saturday evens out a bit. It might just be that the CDC just rolls over the weekend number to Monday instead so the spike stays. That's why it's better to look at a 7 day average. That's what's advised on all the coverage here.