When I enter the exchange date on Line 6 of the form 8824 worksheet, it creates an error that the date is beyond the 180 day limit.

However, the property was in a disaster area and I have the choice to extend the date because of choose either the General Postponement relief under Section 6 or the Alternative relief under Section 17 of Rev. Proc. 2018-58.  

How do I override the error on the worksheet?