and the dates are the same to the second.
dates are stored as double type numbers - the bit after dp representing time as number of seconds divided by the number of seconds in the day (86400). Doubles do not make good fields to join on as you can get very small variations in the actual value which visually is rounded to the nearest second.
suggest try converting the date fields to text using the format function and joining on those instead
Code:
SELECT *
FROM TblA, tblB
WHERE format(tblA.DT,"dd/mm/yyyy hh:nn:ss")= format(tblB.DT,"dd/mm/yyyy hh:nn:ss")
or introduce an element of allowance
Code:
SELECT *
FROM TblA, tblB
WHERE tblA.DT between dateadd('s',-1,tblB.DT) and dateadd('s',1,tblB.DT)