Time interval 1 ::= you are listening to the radio
Time interval 2 ::= you are sleeping
time-int-1 = /fino a che/ not time-int-2 (complementary, null intersection intervals)
If you say : /fino a quando/ the logic is different and you say:
fino a quando mi sono ...
Anyway people mix up these two ways, and we can understand if you place an extra /non/ or you drop it, we will always understand /complentary adjacent intervals/