When we make Savings Plan purchase recommendations, the evaluation timeframe will determine how the calculation takes place. The platform will look back 7 days or 30 days and consider on-demand usage in that time period then use that data as a basis for the projection for the next 7 or 30 days.
If you bought new RI/SP during the historical evaluation period, those new RI/SP are considered as active across the on demand usage in the whole analysis period. These are taken into account in the projection as those new RI/SPs will exist and be active in the next 7 or 30 days.