Used in negative statement to describe a situation that has existed up to this point or up to the present time(adverb)
WordNet. Princeton University. 2010.
Use "up to now" in a sentence
"The extent of this British talent for retreat was hailed by a German military correspondent writing in the Vossische Zeitung: “As long as war exists … [this evacuation] will stand in the eyes of students of the strategy of retreat as a masterpiece which up to now has never been attained.”"
"Kurfürsten Friedrich Wilhelm von Brandenburg (1864 = =), up to now about 20 vols."
"Hence, the need ensues for the Nestlé Company fundamentally to rethink its advertising practices in developing countries as concerns bottle feeding, for its advertising practice up to now can transform a life-saving product into one that is dangerous and life-destroying."