Code/Dax Target values change after a certain date

Hi, 

1. I current have this code for my targets. 

Heavy Clean Period Target =
IF(XXX[DepotName]= "Test Day"&& XXX[Clean Type]="Heavy Clean",70)​

2. I also use a table, which BI talks to excel on OneDrive.

What if a target value changes, after a certain date?

- How would one code/be able to do this with Option 1 above or Option 2

Thanks

Jerry