I usually do this by generating a list of the dates that I need (see
Generating a Sequence in SQL[
^] ) and then using that table in a LEFT JOIN to my actual data table.
E.g.
SELECT ....
FROM MyListOfDates D
LEFT OUTER JOIN biometricdata A ON D.DesiredDate = A.[DATE]
LEFT OUTER JOIN Employees B ON A.employee_id = B.employee_id
Just remember to handle the resulting NULLs returned from A & B for the empty dates