[up to] prep (13c) 1--used as a function word to indicate extension as far as a specified place "sank up to his knees in the mud" 2--used as a function word to indicate a limit or boundary "up to 50,000 copies a month" "worked up to the last minute"
UP TO
Meaning of UP TO in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012