schon (already or yet) may be replaced by "noch" ? in that case when schon means yet.
Maybe one could say that a few hundred years ago, but as far as I know, today we do not.
I was under the impression it was "on the clock" but maybe it is "of the clock"
It means "of the clock," similar to Good Bye originally meaning "God be with ye."
"It is already 9 hours" isn't English. You have to say "It has already been 9 hours".