Parameter value not passed correctly to a query

[Dean C]

I've added some php and code tags to your post to make it a little more readable. I'm going to bed now and will take a look in the morning if I get a chance

Edit:

Ok i see your error already, you have to define the calculated field within your first batch of SQL. So add this to the first part of the sql:

(w.warned_time+wt.warn_maturity*24*60*60) AS calculated_field

Then add this clause:

ORDER BY calculated_field DESC