SQL Server 2017

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CREATE TABLE T(
   EmployeeID INT,
   [Date] Date,
   Login DATETIME,
   Logout DATETIME
);

INSERT INTO T VALUES (123,'10/31/2018','10/31/2018 8:30','10/31/2018 10:35');
INSERT INTO T VALUES (234,'10/31/2018','10/31/2018 9:30','10/31/2018 11:37');
INSERT INTO T VALUES (345,'10/31/2018','10/31/2018 9:00','10/31/2018 11:09');

;WITH CTE AS (
   SELECT [Date],Login,Logout 
   FROM T
   UNION ALL
   SELECT [Date],DATEADD(mi, 30, Login) ,Logout
   FROM CTE 
   WHERE  DATEADD(mi, 30, Login) < Logout
),CelanderCte AS(
    SELECT *, CAST(Login AS TIME) LoginTitme
    FROM CTE
)

SELECT convert(char(10), [Date], 101) 'DATE',
	COUNT(CASE WHEN LoginTitme >= '8:30' AND LoginTitme < '9:00'    THEN 1 END) '8:30:00 AM',
	COUNT(CASE WHEN LoginTitme >= '9:00' AND LoginTitme < '9:30'    THEN 1 END) '9:00:00 AM',
	COUNT(CASE WHEN LoginTitme >= '9:30' AND LoginTitme < '10:00'   THEN 1 END) '9:30:00 AM',
	COUNT(CASE WHEN LoginTitme >= '10:00' AND LoginTitme < '10:30'  THEN 1 END) '10:00:00 AM',
	COUNT(CASE WHEN LoginTitme >= '10:30' AND  LoginTitme <'11:00'  THEN 1 END) '10:30:00 AM',
        COUNT(CASE WHEN LoginTitme >= '11:00' AND  LoginTitme <'11:30'  THEN 1 END) '11:00:00 AM'
FROM CelanderCte
GROUP BY CONVERT(char(10), [Date],101)

DATE	8:30:00 AM	9:00:00 AM	9:30:00 AM	10:00:00 AM	10:30:00 AM	11:00:00 AM
10/31/2018	1	2	3	3	3	2

Warning: Null value is eliminated by an aggregate or other SET operation.