INSERT INTO @t VALUES

(761058840, '2018-01-02 07:54:28.000', '2018-01-02 08:33:34.000'),

(761058840, '2018-01-02 07:54:28.000', '2018-01-02 08:36:30.000'),

(761058840, '2018-01-02 08:33:45.000', '2018-01-02 08:35:30.000'),

(761058840, '2018-01-02 13:11:18.000', '2018-01-02 13:14:04.000'),

(761058840, '2018-01-02 13:11:18.000', '2018-01-02 13:39:40.000'),

(761058840, '2018-01-02 13:22:11.000', '2018-01-02 13:40:25.000'),

(761058840, '2018-01-02 15:56:18.000', '2018-01-02 15:59:34.000'),

(761058840, '2018-01-02 15:56:18.000', '2018-01-02 16:36:25.000'),

(761058840, '2018-01-02 16:01:34.000', '2018-01-02 16:05:34.000'),

(761058840, '2018-01-02 16:33:19.000', '2018-01-02 16:38:26.000'),

(761058840, '2018-01-02 21:20:25.000', '2018-01-02 21:24:25.000'),

(761058840, '2018-01-02 22:20:36.000', '2018-01-03 05:20:37.000'),

(761058840, '2018-01-02 22:20:36.000', '2018-01-03 05:20:37.000'),

(761058840, '2018-01-03 08:31:29.000', '2018-01-03 09:01:10.000'),

(761058840, '2018-01-03 08:31:59.000', '2018-01-03 09:01:07.000'),

(761058840, '2018-01-03 09:01:57.000', '2018-01-03 09:06:27.000'),

(761058840, '2018-01-03 14:07:27.000', '2018-01-03 14:17:32.000'),

(761058840, '2018-01-03 14:09:28.000', '2018-01-03 14:45:00.000'),

(761058840, '2018-01-03 14:19:32.000', '2018-01-03 14:48:22.000'),

(761058840, '2018-01-03 17:30:38.000', '2018-01-03 18:06:35.000'),

(761058840, '2018-01-03 17:33:54.000', '2018-01-03 18:09:48.000');

WITH t_with_change AS (

SELECT id, timeOn, timeOff, CASE WHEN MAX(timeOff) OVER (PARTITION BY ID ORDER BY timeOn ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING) >= timeOn THEN 0 ELSE 1 END AS chg

FROM @t

), t_with_groups AS(

SELECT id, timeOn, timeOff, SUM(chg) OVER (PARTITION BY ID ORDER BY timeOn) AS grp

FROM t_with_change

)

SELECT id, grp, MIN(timeOn) AS timeOn, MAX(timeOff) AS timeOff

FROM t_with_groups

GROUP BY id, grp