Query Parameter throws General Error

Set up a query in Excel 13 that works with a hardcoded number, but fails when I pass a parameter. I'm trying to bring in database entries that are more than one day old.

What am I doing wrong?

krntime stores a text string date like this:
[FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]SELECT *
FROM RTDB.dbo.remote remote
WHERE krntime < NOW() - ? <============= [ATI][OpenRDA ODBC]Invalid date/time expression
[/FONT]

BTW also tried to use a parameter that points to worksheet cell where the value is = NOW() - 1

Same error