On SQL-Server, dates must be enclosed with single quote ' instead of the
pound sign #.  With the correct option set, you can also use the double
quote " but it's better to stick with the standard.

You must use the international date format, yyyy/mm/dd or the US format,
mm/dd/yyyy or mm/dd/yy if the default language for the login is english;
otherwise you must use an appropriate format.

The trouble with DateTime and SmallDateTime is that they have both a time
part that may be different from midnight; something that may cause a lot of
problem when used with the equality operator = .  The convert function can
be used to strip away this time part; use a second call to the convert
function to convert back to a DateTime or SmallDateTime field if you don't
want some missy resultats with > and < .

Finally, the best way is not to construct the query string but to use a
query with parameters; as this will shield you from potential localization
problems (and security/hacking problems, too).