How to use DECLARE in SSIS

Hello All,

Till now i have used packages to load data using SELECT statement, but now i need to DECLARE a date before the SELECT and i can run it fine in the management studio, but cannot in SSIS. Can someone please tell me if i have to use some other task before the data flow task. My sql is like below.

Thanks

DECLARE @d DATE = CASE WHEN DATEPART(DW, GETDATE()) = 2
                       THEN DATEADD(D, -3, GETDATE())
                       ELSE DATEADD(D, -1, GETDATE())
                  END;
SELECT STATEMENT