Yes, there's ambiguity, but there's no reason to introduce new ambiguity where none existed before by trying to reason about these words in terms of midnight (possibly for the benefit of computers), when that was never where these words were anchored. That was the point I was trying to make.
I've always reasoned in terms of midnight because that's when the date changes. I use tomorrow to mean the next date and today to mean the current date. I'm not doing it for the sake of computers, that's just what I've always understood these words to mean.
I think using midnight as the anchor for the today/tomorrow distinction is a lot less confusing and ambiguous than having today/tomorrow not tied to the current date.
