Hi John,
I wonder if you can help me any further? I've joined on RowNo + 1 but now it misses off the 3rd Username. (It only brings back 2 records instead of 3)
Here's the amended code....have you any ideas

DECLARE @Contents varchar(4000)
SET @Contents =
'abcdef 01/01/2018 08:15:13 This is a note , this is a note , this is a note , this is a note , this is a note , this is a note , this is a note, ghijkl 02/02/2018 12:15:45, this is a note , this is a note , this is a note , this is a note mnopqr 03/02/2018 10:34:23 this is a note this is a note this is a note this is a note this is a note this is a note';

WITH Ten AS (
  SELECT n FROM (VALUES (1), (2), (3), (4), (5), (6), (7), (8), (9), (0)) v(n)
  )
, Hundred AS (
  SELECT t1.n
  FROM Ten t1
  CROSS JOIN Ten t2
  )
, Thousand(n) AS (
  SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
  FROM Hundred h
  CROSS JOIN Ten t
  )
, StartPoints AS (
  SELECT n AS StartChar, ROW_NUMBER() OVER(ORDER BY n) AS Row#
  FROM Thousand
  WHERE SUBSTRING(@Contents,n,7) LIKE '[a-z][a-z][a-z][a-z][a-z][a-z] '
  AND ISDATE(SUBSTRING(@Contents,n+7,19)) = 1
  AND n<= LEN(@Contents) - 26
  )
, StartPointssandNext AS (
  SELECT
   StartPoints.StartChar AS NextStartChar,
   sp2.StartChar AS StartChar
  FROM StartPoints
  JOIN StartPoints sp2 ON StartPoints.Row# = sp2.Row# + 1
  )
SELECT
  SUBSTRING(@Contents,StartChar,NextStartChar-StartChar)
FROM StartPointssandNext