You are, of course, correct. And my round figure of 60 days is only a round figure. Anyone who is interested can try it themselves, with as much accuracy as they needed.
I had actually noted this the |irst time I tried to comment, but I went to log in, and my comment evaporated.
Specifically, I had said that if you believed the data, it was 60 day doubling. But if you didn't, you had to go back to the previous curve.
We will find out, in time, whether the infection rate was on the slower curve shown, or at the faster, previous rate.