Merge two fields from two query's to one

Hi all,
i have two Query’s from Service-Now datasource.
Both query’s (change_task and change_request) deliver a date field.
For query A, the date field is named “due_date”
For query B, the date field is a customized “u_xxxxx_date”

As we want to show the results from both Query’s in a business calendar, we need a single field with the date.

I tried several ways, nonw succeeded. The best result was using “Add field from calculation”, but the output is not really what i expect :wink:

Any idea?
Thanks in advance