ID   Code Date

  5525  X   2010-10-07
  5525  Y   2010-11-25
  5525  Y   2010-11-29
  5525  Y   2010-10-06
**5525  X   2011-01-14**
**5525  X   2011-01-31**
  5525  Y   2010-12-09
  5525  Y   2010-10-15
  5525  X   2010-10-18
  5525  Y   2010-12-08
  5525  X   2010-12-09

select ID from table
where code in (X,Y)
and date <= DATEADD(dd, -540, CURRENT_TIMESTAMP)

SELECT t1.ID FROM table_x t1
 WHERE
    t1.Date <= DATEADD(dd, -540, CURRENT_TIMESTAMP) AND
    -- you can add other criterias here as well, like t1.Code in (X,Y)
    t1.ID NOT IN (
       SELECT ID FROM table_x t2
        WHERE
          t2.Date > DATEADD(dd, -540, CURRENT_TIMESTAMP)
          -- you can add other criterias here as well, like t2.Code in (Z,F)
    );

SELECT *
FROM table1
WHERE id NOT IN (
    SELECT id
    FROM table1
    WHERE Date <= DATEADD(dd, -540, CURRENT_TIMESTAMP)
)
AND code in ('X','Y')

SELECT ID, Code, [Date]
FROM tablename t
WHERE NOT EXISTS (
    SELECT *
    FROM tablename
    WHERE ID = t.ID AND NOT (
        Code IN ('X','Y')
        AND [Date] <= DATEADD(dd, -540, CURRENT_TIMESTAMP))
)