Learning Plan ILT Event "Due Dates" added when not requested

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I'm creating a New Hire Learning Plan, which I would like to roll out soon; however, and when adding ILT Events to the Learning Plan with a 12-month time-frame completion date, a "Due Date" is automatically added.

Any ideas on how to override this?  I don't have the option to enter a N/A in the field, as a calendar pops up prompting me to choose a date.  If no date is chosen it automatically adds a due date in 30 days from the date the ILT Event is added.