If I were to write the query (which was )

SELECT *

FROM #DateTest

WHERE SampleDate BETWEEN @DATE1 AND @DATE2

I would have written it

SELECT *

FROM #DateTest

WHERE SampleDate >= @DATE1

AND SampleDate < (@DATE2 + 1)

That way I don't get into strife when my data contains a time that is greater than 23:59 and less than the start of the next day. Obviously I would have to remember to sanitise my inputs to ensure that the @date2 value coming in was a whole date (had no time fraction). Sorry I wasn't clearer earlier.

EDIT! EDIT! EDIT! I would have written it this way assuming of course that I wanted to return all the activity on @DATE2.