LAST_EVENT_PROC_DT (numeric(8,0),not null)

'' + '|' +
'' + '|' +
cast(q.NEXT_EVENT_PROC_DT as varchar) + '|' + -- Due Date
cast(q.LAST_EVENT_PROC_DT +12 as varchar) + '|' + -- Disco Date = Due date +15
CONVERT(VARCHAR(10),GETDATE() +15,112) + '|' + -- Agency Send Date todays date + 15

SET NOCOUNT ON

CREATE TABLE #Dates (
  d DATE,
  isWeekend BIT,
  PRIMARY KEY (d)
)
DECLARE @dIncr DATE = '2000-01-01'
DECLARE @dEnd DATE = '2100-01-01'


WHILE ( @dIncr < @dEnd )
BEGIN

  INSERT INTO #Dates (d, isWeekend) VALUES( @dIncr,  IIF(DATEPART(WEEKDAY, @dIncr) IN (7, 1), 1, 0 ))
  SELECT @dIncr = DATEADD(DAY, 1, @dIncr )
END

SELECT
  '' + '|' +
  '' + '|' +
  cast(q.NEXT_EVENT_PROC_DT as varchar) + '|' + -- Due Date
  cast(dates.d as varchar) + '|' + -- Disco Date = Due date +15
  CONVERT(VARCHAR(10),GETDATE() +15,112) + '|' + -- Agency Send Date todays date + 15
  ...
FROM <TABLE>
CROSS APPLY
(
  SELECT TOP 1 d
  FROM #Dates AS dates
  LEFT OUTER JOIN <holidays> ON holidays.date = dates.d
  WHERE d >= DATEADD(DAY, 12, CAST(CONVERT(CHAR(8), q.LAST_EVENT_PROC_DT) AS DATE))
    AND d.IsWeekend = 0
    AND holidays.date IS NULL
  ORDER BY d ASC
) AS dates