declare @e table (E_CODE VARCHAR(10), [DATE] VARCHAR(10), S_TIME VARCHAR(5), DURATION INT );

INSERT INTO @e VALUES ( 'JOHN', '2014/12/20', '08:00', 1);
INSERT INTO @e VALUES ( 'JOHN', '2014/12/20', '08:01', 1);
INSERT INTO @e VALUES ( 'JOHN', '2014/12/20', '08:02', 58);
INSERT INTO @e VALUES ( 'JOHN', '2014/12/20', '09:00', 30);
INSERT INTO @e VALUES ( 'JOHN', '2014/12/20', '10:00', 45);
INSERT INTO @e VALUES ( 'JACK', '2014/12/20', '08:00', 120);
INSERT INTO @e VALUES ( 'JACK', '2014/12/20', '10:10', 60);
INSERT INTO @e VALUES ( 'JACK', '2014/12/20', '11:30', 60);

SELECT DISTINCT e3.e_code
              , e3.date
  FROM(
       SELECT e2.E_CODE
            , e2.DATE
            , e2.S_TIME
            , CASE
              WHEN e2.s_time = DATEADD(minute, e2.lag_dur, e2.lag_time) 
			    OR e2.lag_time IS NULL THEN SUM(e2.duration)
					OVER(PARTITION BY e2.e_code, e2.date 
					     ORDER BY e2.s_time 
						 ROWS UNBOUNDED PRECEDING)
                  ELSE 0
              END AS sum_dur
         FROM(
       SELECT e1.e_code
            , e1.date
            , e1.s_time
            , e1.DURATION
            , lag(e1.s_time, 1, NULL) OVER(PARTITION BY e1.e_code, e1.date 
			                               ORDER BY s_time) AS lag_time
            , lag(e1.duration, 1, 0)  OVER(PARTITION BY e1.e_code, e1.date 
			                               ORDER BY s_time) AS lag_dur
         FROM @e e1
		 ) e2
	) e3
  WHERE e3.sum_dur >= 90;