The monitor comes off "on Thursday"

timeline_event

texture · prob. 19 Nov YDAU (reported 20 Nov)

When: the removal procedure "on Thursday" — prob. Thu 19 Nov YDAU (inference); reported to Hal on 20 Nov.
What: The resolution of the eleven-day imprisonment arrives as an offhand relayed datum: "Otis P. Lord had undergone a procedure for the removal of the Hitachi monitor on Thursday, LaMont Chu had said."