Access Linked To SQL Server - 2 Day Offset Error

We recently translated the backend db from Access(97) to SQL Server.
We are still using Access frontends. I have an update query in the
Access front end that uses a lookup table to populate fields. The
common fields between the table and the lookup table are the primary
key (LocID) and date & time fields. The query is:

UPDATE tblPT_Offsets INNER JOIN tblPT ON tblPT_Offsets.LocID =
tblPT.LocID SET tblPT.Offset_ft = [tblPT_Offsets].[Offset_ft],
tblPT.Salinity = [tblPT_Offsets].[Salinity]
WHERE (((tblPT.Offset_ft) Is Null) AND ((tblPT.Salinity) Is Null) AND
((Format([Date]+[Time],"mm/dd/yy hh:nn")) Between [StartDate] And
[EndDate]));

This worked fine in Access and seemed to work fine after switching to
Access, but on closer look, there is exactly a 2 day error being
introduced. A quick search of the newsgroups brings up lots of Access
to SQL date problems, but a 2 day offset seems rather strange? Any
ideas??

I know the field names Date and Time are inappropriate, but legacy
issues are a pain in the butt to resolve!! Could this be a problem?

David