Most feature movies shown during the prime time and early overnight hours (8:00 p.m. to 2:30 a.m. Eastern Time) are presented by film historian Robert Osborne (who has been with the network since its 1994 launch, except for a five-month medical leave from July to December 2011, when guest hosts presented each night's films) on Sunday through Wednesday evenings – with Osborne only presenting primetime films on weekends – and Ben Mankiewicz presenting only late evening films on Thursdays, and the "Silent Sunday Nights" and "TCM Imports" blocks on Sundays.

What is the time period covered by prime time and the early overnight?