Power BI: Apply % decrease at specific date in forecast

Question

I've been working on this problem for a couple of days and can't find a solution.

I have 3 tables:

• Table1 with a number of "sales" from January to December 2021 by "product"
• Table2 with "end of production date" + "consumers" (I'll get back to that later)
• Table3 with a calendar (Date, year, month, quarter, etc.)

We want to forecast the monthly sales up to 2023. So I created a forecast with Table1 data. However, we know that sometime between 2022 and 2023 at specific quarters some of the products will no longer exist. Each product has specific number of consumers from 1 to 4. So I created a "Switch" measure in order to decrease by X% depending on the number of consumers (1 = -100%, 2=-50%, etc.)

Here is my problem: The % decrease in the forecast needs to be applied at a specific date (quarter) mentioned in Table2. Sometimes all at once, sometimes -50% at Qn1 and -50% at Qn2, etc.

I can't seem to find a way to apply my % decrease to my forecast at the specific date mentioned in Table2.

I hope this makes sense,

Thanks a lot for your help!