XML Chart x axis date plot for empty values

I plot actual date and due date for a number of records and chart the result However, where actual date is blank, thr x axis plots from 1900 so skewing the chart.

I want to limit the start of the x axis to another field on the record titled Application_date.

What xml code do I need to insert to start the x axis date to Application_date.

Any help would be appreciated.

Jim

Jim