Line 14 (part of phisical presence test) requires you to list time you was in US during the year. So some reason it does not allow 0 as input for number of days on business.
I did not find anything that supports this requirement.
Case "I worked abroad, visited US on holidays so no US-based income was recieved" cannot be correctly reflected.
I can input 1 day on business 0 usd income, but that would not be 100% correct. Can you please change that form.
This applied to TurboTax Online, Turbotax Deluxe.
(It is also the same for Turbotax 2018, which will require me to basically re-do the form 2555 manually)