>It is my understanding that the result of {^3000/01/01}-EFFDATE
>,which is a date - a date, is a number.
>
>am I wrong???

Oops, put that one down to tiredness :)

But with the error being in the Dataenvironment.OpenTables it will be an index expression that is wrong I would say.

Where does EFFDate come from?
Is it a field?