@corriedrummond that has been a quirk for quite some time --- it will not accept a zero business days . At the same for purposes of form 2555 it really changes nothing --- so show your US arrival date and departure date, show 1 day in business and the rest will become non-business days. This may result one day's worth Foreign Earned income being allocated to US source rather excludable and foreign source.
Just keep the software happy.
BTW -- which country is your tax home ?
Is there more one can do for you ?
