(the chart has daily resolution btw)
Assuming weekly seasonality, is it ok to get the exact day when the increase was noticed and the day 1 week earlier, compute a scaling factor new/old and scale everything before the increase happened with that scaling factor ?
How is this operation usually called ? How do people usually do this, is it just this sort of scaling or is there a more correct(and perhaps more sophisticated) approach for this ?
(The two increases have a common cause. The chart shows counts of certain posts on a website. At the times of the two increases, there was a new roll-out of a collector and as a result, more data started coming in. So the scaling I'm trying to do is trying to estimate how the time-series would have looked prior to the increases if the current collection were in place from the beginning, from January 2015)