DAT03 Historic Volume
On DAT03 Historic Volumes my volume line item don't match with the values for FY20 but does match with Offset volumes for Fy20. I used the following formula:
IF 'SYS01 Time Settings By Week'.'1st Forecast Year?' THEN OFFSET(Volumes, -52, 0) ELSE 0.
And, also DEM03 demand forecast pulls only FY20 data not FY21, used the attached time settings: