Union Query - Undefined

I am trying to run the following query but I get a "Variable CALID (Replace CALID with any variable) is undefined"

If I do a cfdump the query returns the right results.

If I do each query seperatly I do not get the undefined error.

However, when I add use the UNION to combine the queries, I get the undefined error.

The query is as follows:

<cfquery name="Testunion" datasource="cscms">
SELECT AGREEMENT_END_DATE, ID
FROM Data1
WHERE Data1.AGREEMENT_END_DATE IS NOT NULL AND Data1.AGREEMENT_END_DATE Between Now() and Now ()+360 AND Data1.REQUESTING_DEPT = 'IT'

UNION ALL

SELECT EventDate, CalID
From Calen
WHERE Calen.EventDate IS NOT NULL

ORDER BY Data1.CONTRACT_END_DATE, Data1.ID, Calen. EventDate
</cfquery>

------------------------

Now maybe there is a better way to this, but I am trying to take the information from the Data1 Table and the Calen Table and display it in rows by date order.

Any help would be greatly appreciated, I spent enough time trying to figure this out already, so that must mean the answer is simple.

General SQL debugging tips:

1. Run the query in your SQL tool to confirm it works.
2. Confirm the data types of all columns and adjust the SQL accordingly.
3. If necessary, remove all columns from the query except one, and run it. If it runs successfully, add one more column and test again. Continue adding one column at a time until you discover the field that is causing the error.