Denna lösning tillhandahåller CONVERT_IMPLICIT-drift för ditt tillstånd i predikat
SELECT *
FROM xxx
WHERE CAST(dates AS date) BETWEEN '1/1/2013' and '1/2/2013'
ELLER
SELECT *
FROM xxx
WHERE CONVERT(date, dates, 101) BETWEEN '1/1/2013' and '1/2/2013'
Demo på SQLFiddle