Not being an expert in epidemiology, I dont know what R0 even refers to. Barring you or exdemmom explaining, Ill presume its the point of inflection she keeps referring too where the infection rate starts to drop off.
As for engineering applications, Im not expecting this epidermic to have regular periodic. As a matter of fact, it includes human behaviors with no real good models at all. If you trace back the conversation it started with dont try to extrapolate from interpolation solutions. I did not suggest Fourier analysis. I suggested a low order Fourier fit might model the long term epidemic rise and fall.
Maybe you can do a better job of explaining how fitting the daily infection rate is going to provide a prediction of future rates than exdemmom. Seems to me you cant predict until the inflection point has occurred or slightly after since R isnt going to exponential until then. So you can collect data for a model to be used next time, but this model doesnt get one to prediction all by itself.
As to apologies, I think I was about as polite and explanatory as one could be. And exdemmom was given every opportunity to carry on.