You need to quote your dates in your SQL statement:
sqlstmt = "SELECT * FROM projectx WHERE sdate BETWEEN '" & _
fdate & "' AND '" & tdate & "'"
For example, if fdate is 2003-01-01 and tdate is 2004-01-01 then the SQL statement that will be executed will be:
SELECT * FROM projectx WHERE sdate BETWEEN '2003-01-01' AND '2004-01-01'
You may also want to check that the dates in your variables are formatted correctly for your installation, for example US or UK date format.