Lookup value in Query

Question

I'm trying to replace the local variables i've declared below to capture them in calculated columns.

So the [YTD] column would look up Today's Date - 1 and return the [FiscalDayOfYear] making everything in that column less than that "YTD" and anything greater "NA"

DECLARE @ytd FLOAT = 124
DECLARE @monthly FLOAT = 4

SELECT *
FROM(
 SELECT [Date]
      ,[FiscalDayOfYear]
      ,[FiscalYear]
      ,[FiscalMonthNumber]
      ,[FiscalWeekNumber]
      ,[YTD] = IIF([FiscalDayOfYear] <= @ytd, 'YTD','NA')
      ,[MTD] = IIF(([FiscalDayOfYear] <= @ytd) AND ([FiscalMonthNumber] = @monthly), 'MTD','NA')
  FROM [DL].[Date]
 WHERE  CONVERT(date,Date) >= '2018-01-01') AS DT
UNPIVOT 
(
  [FLAG] FOR FLAGS IN ([YTD], [MTD])
) AS pivoted_tbl
WHERE [FLAG] != 'NA'

Because of our fiscal calendar I can't just use the Date column I've got to compare to day of year in our calendar.