If we execute the query with given data

SELECT [InsertedOn]

FROM MyLogs

WHERE [InsertedOn] BETWEEN '20090131' AND '20090131 23:59:59:999'

The output is as follows...

2009-01-31 00:00:00.000

2009-01-31 00:01:01.000

2009-01-31 12:59:59.127

2009-01-31 00:01:01.000

2009-01-31 13:00:00.997

2009-01-31 00:01:01.127

2009-02-01 00:00:00.000

2009-01-31 00:01:01.000

2009-01-31 21:59:58.347

2009-01-31 23:59:59.997

2009-01-31 00:01:01.000

2009-01-31 21:59:58.347

2009-02-01 00:00:00.000

2009-01-31 00:01:01.000

2009-01-31 22:59:58.347

2009-01-31 09:01:30.347

2009-02-01 00:00:00.000

with the above result the answer for the given questions will contain the value 2009-02-01 00:00:00.000.....

will not contain the following value

2009-01-30 00:00:00.000