Overwrite Header Est Del Date with Blank Date or Past Date - System Option

>Utilities>System Options>Schedule Pro>Order Entry

Category-Data Transfer

Type-Must be Global 

If Update the Order Header Estimated Delivery Date is set to yes, the program will keep the Order Header Est Del Date updated unless a job is changed to a date that has passed (for example, correcting an error on the schedule after the fact) or the job has been deleted from the schedule. 

If this option is set to Yes, the Header Date will be updated in all cases, even if the change is to a past or blank date.