CREATE TABLE tmp_end_date
(ID INT,
tgs_rec_eff_dt DATE)

GO

insert into tmp_end_date values(1300505,'2012-08-01 15:57:15')
insert into tmp_end_date values(1300505,'2012-08-01 15:55:16')
insert into tmp_end_date values(1300505,'2012-07-30 11:29:34')
insert into tmp_end_date values(1300505,'1905-07-01')

GO

WITH aa AS
(
SELECT ID,tgs_rec_eff_dt FROM tmp_end_date
)
SELECT 
     ROW_NUMBER()over(partition by ID order by tgs_rec_eff_dt) rownumber,
     ID,
     tgs_rec_eff_dt,
     NULL as end_date     ---populate based on start date of next record - 1
FROM aa

CREATE TABLE tmp_end_date(ID INT,tgs_rec_eff_dt DATETIME);
INSERT INTO tmp_end_date 
SELECT ID, tgs_rec_eff_dt
FROM (VALUES(1300505,'2012-08-01 15:57:15'),(1300505,'2012-08-01 15:55:16'),
            (1300505,'2012-07-30 11:29:34'),(1300505,'1905-07-01'))a(ID, tgs_rec_eff_dt);

SELECT a.ID, a.tgs_rec_eff_dt AS startDate, b.tgs_rec_eff_dt AS endDate
FROM tmp_end_date a
OUTER APPLY (SELECT TOP 1 tgs_rec_eff_dt
             FROM tmp_end_date b
             WHERE a.tgs_rec_eff_dt < tgs_rec_eff_dt
             ORDER BY tgs_rec_eff_dt ASC) b;

ID          startDate               endDate
----------- ----------------------- -----------------------
1300505     2012-08-01 15:57:15.000 NULL
1300505     2012-08-01 15:55:16.000 2012-08-01 15:57:15.000
1300505     2012-07-30 11:29:34.000 2012-08-01 15:55:16.000
1300505     1905-07-01 00:00:00.000 2012-07-30 11:29:34.000