t-sql 2012 change logic to not be a cte

CTEs don't "nest" like that... The syntax looks more like this...

 ;WITH Daily_CTE AS (
        >>Your SELECT big query here<<
  ), ABSResults AS (
        SELECT  
                perID, 
                [date],
                CAST(CASE 
                        WHEN code IN ('GOT','SSS','UNV') 
                        THEN CASE
                                        WHEN SUM(absentMinutes) / dayMinutes > 1 
                                        THEN 1
                    ELSE SUM(absentMinutes) / dayMinutes
                                END
                        ELSE 0
                END AS DECIMAL(8,3)) UnDays       
         FROM Daily_CTE
         GROUP BY perID,  [date], code, dayMinutes
         ORDER BY  perID, [date] DESC 
)
UPDATE Atrn SET Atrn.ABS = ABSResults.UnDays
FROM
        dbo.AtnDet Atrn
        JOIN ABSResults
                ON Atrn.perID = ABSResults.perID AND Atrn.[date] = ABSResults.[date]
WHERE
        Atrn.ABS <> ABSResults.UnDays OR Atrn.ABS IS NULL

---

Jason Long