Related Clues:

• When 51-Across starts, for many
• When 13-Across aired for most of its run
• Hr. when many workdays begin
• When typical workdays start
• When the workday, or nightly news, may start
• When work starts, for many
• Common starting hr
• When a prime-time drama might air
• Time slot with talk shows
• When some office workers start
• Starting hr. for some
• Starting hour, perhaps