-- Setup
IF OBJECT_ID('tempdb..#x') IS NOT NULL
	DROP TABLE #x;

CREATE TABLE #x 
( Studentid int, DateID bigint unique, attendaceind bit)

INSERT INTO #x
	SELECT 1234, 20121031, 1 UNION ALL
	SELECT 1234, 20121102, 1 UNION ALL
	SELECT 1234, 20121101, 1 UNION ALL
	SELECT 1234, 20121105, 0 UNION ALL
	SELECT 1234, 20121107, 1 UNION ALL
	SELECT 1234, 20121108, 1 UNION ALL
	SELECT 1234, 20121109, 0 UNION ALL
	SELECT 1234, 20121113, 0 UNION ALL
	SELECT 1234, 20121115, 0 UNION ALL
	SELECT 1234, 20121114, 0 UNION ALL
	SELECT 1234, 20121116, 0 UNION ALL
	SELECT 1234, 20121119, 0 UNION ALL
	SELECT 1234, 20121120, 0 UNION ALL
	SELECT 1234, 20121126, 0 UNION ALL
	SELECT 1234, 20121127, 0 UNION ALL
	SELECT 1234, 20121128, 0 UNION ALL
	SELECT 1234, 20121129, 0 UNION ALL
	SELECT 1234, 20121130, 0 UNION ALL
	SELECT 1234, 20121203, 0 UNION ALL
	SELECT 1234, 20121204, 0 UNION ALL
	SELECT 1234, 20121205, 0 UNION ALL
	SELECT 1234, 20121206, 0 UNION ALL
	SELECT 1234, 20121207, 0 UNION ALL
	SELECT 1234, 20121210, 0 UNION ALL
	SELECT 1234, 20121211, 0 UNION ALL
	SELECT 1234, 20121212, 0 UNION ALL
	SELECT 1234, 20121213, 0 UNION ALL
	SELECT 1234, 20121214, 1 UNION ALL
	SELECT 1234, 20121217, 1 UNION ALL
	SELECT 1234, 20121218, 1 UNION ALL
	SELECT 1234, 20121219, 1 
GO

DECLARE @startdate bigint=20121113,
		@endDate bigint=20121213;

;WITH answer AS
(	SELECT	StudentID, COUNT(*) AS DaysAbs
	FROM #x 
	WHERE DateID>=@startdate AND DateID<=@endDate
	AND attendaceind=0
	GROUP BY Studentid
)
SELECT StudentID, @startdate AS startdate, @endDate AS endDate, DaysAbs
FROM answer
GO

DECLARE @startdate bigint=20121101,
		@endDate bigint=20121130;

;WITH 
notthere AS
(	SELECT	StudentID, COUNT(*) AS DaysAbs
	FROM #x 
	WHERE DateID>=@startdate AND DateID<=@endDate
	AND attendaceind=0
	GROUP BY Studentid
),
wasthere AS
(	SELECT	StudentID, COUNT(*) AS DaysIn
	FROM #x 
	WHERE DateID>=@startdate AND DateID<=@endDate
	AND attendaceind=1
	GROUP BY Studentid
)
SELECT nt.StudentID, @startdate AS startdate, @endDate AS endDate, nt.DaysAbs, wt.DaysIn
FROM notthere nt
OUTER APPLY wasthere wt

StudentID   startdate            endDate              DaysAbs     DaysIn
----------- -------------------- -------------------- ----------- -----------
1234        20121101             20121130             13          4

SELECT
    Studentid,
    MIN(dateid) AS First_Absence_Date,
    MAX(dateid) AS Last_Absence_Date,    
    COUNT(*) AS Total_Consecutive_Absences
FROM (
    SELECT
        Studentid, attendanceind, dateid,
        ROW_NUMBER() OVER (PARTITION BY Studentid ORDER BY dateid) -
        ROW_NUMBER() OVER (PARTITION BY Studentid, attendanceind ORDER BY dateid) AS Grp#
    FROM #x x --<<-- change to your table name
) AS derived
WHERE
    attendanceind = 0
GROUP BY
    Studentid, grp#
HAVING
    COUNT(*) >= 15
ORDER BY
    Studentid, First_Absence_Date

-- Setup
IF OBJECT_ID('tempdb..#x') IS NOT NULL
	DROP TABLE #x;

CREATE TABLE #x 
( Studentid int, DateID DATE unique, attendaceind bit)

INSERT INTO #x
	SELECT 1234, '20121031', 1 UNION ALL
	SELECT 1234, '20121102', 1 UNION ALL
	SELECT 1234, '20121101', 1 UNION ALL
	SELECT 1234, '20121105', 0 UNION ALL
	SELECT 1234, '20121107', 1 UNION ALL
	SELECT 1234, '20121108', 1 UNION ALL
	SELECT 1234, '20121109', 0 UNION ALL
	SELECT 1234, '20121113', 0 UNION ALL
	SELECT 1234, '20121115', 0 UNION ALL
	SELECT 1234, '20121114', 0 UNION ALL
	SELECT 1234, '20121116', 0 UNION ALL
	SELECT 1234, '20121119', 0 UNION ALL
	SELECT 1234, '20121120', 0 UNION ALL
	SELECT 1234, '20121126', 0 UNION ALL
	SELECT 1234, '20121127', 0 UNION ALL
	SELECT 1234, '20121128', 0 UNION ALL
	SELECT 1234, '20121129', 0 UNION ALL
	SELECT 1234, '20121130', 0 UNION ALL
	SELECT 1234, '20121203', 0 UNION ALL
	SELECT 1234, '20121204', 0 UNION ALL
	SELECT 1234, '20121205', 0 UNION ALL
	SELECT 1234, '20121206', 0 UNION ALL
	SELECT 1234, '20121207', 0 UNION ALL
	SELECT 1234, '20121210', 0 UNION ALL
	SELECT 1234, '20121211', 0 UNION ALL
	SELECT 1234, '20121212', 0 UNION ALL
	SELECT 1234, '20121213', 0 UNION ALL
	SELECT 1234, '20121214', 1 UNION ALL
	SELECT 1234, '20121217', 1 UNION ALL
	SELECT 1234, '20121218', 1 UNION ALL
	SELECT 1234, '20121219', 1 
GO

DECLARE @startdate DATE='20121114',
		@endDate DATE='20121213';

--;WITH Absences AS (
    SELECT StudentID, StartDT=MIN(DateID), EndDT=MAX(DateID)
        ,Absences=COUNT(1-attendaceind)
    FROM (
        SELECT StudentID, DateID, attendaceind
            ,n=DATEDIFF(day, DateID
                ,ROW_NUMBER() OVER (PARTITION BY StudentID ORDER BY DateID))
        FROM #x
        WHERE attendaceind = 0) a
    GROUP BY StudentID, n
--    )
--SELECT StudentID, StartDT=MIN(StartDT), EndDT=MAX(EndDT)
--    ,Absences=SUM(Absences)
--FROM (
--    SELECT StudentID, StartDT, EndDT
--        ,Absences=CASE WHEN StartDT >= @startdate AND EndDT <= @enddate THEN Absences
--            WHEN StartDT < @startdate AND EndDT <= @enddate 
--                THEN DATEDIFF(day, @startdate, EndDT)
--            WHEN StartDT >= @startdate AND EndDT > @enddate 
--                THEN DATEDIFF(day, StartDT, @enddate)
--            ELSE DATEDIFF(day, @startdate, @enddate) END
--    FROM Absences
--    WHERE EndDT >= @startdate AND StartDT <= @enddate) a
--GROUP BY StudentID

DROP TABLE #x