No later than (4)
(Other definitions for upto that I've seen before include "Capable of or engaged in" , "As far as; ready for" , "Capable of; dependent on" , "Pout being occupied with" , "'Having the requisite qualities for (2,2)'" .)
'no later than' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for until that I've seen before include "Not beyond (hour)" , "As late as" , "Pending such time as" , "As far as" , "Up to (a point in time)" .)