Related Clues:

• Zero hour for Will Kane, in a film
• Lunch time, maybe
• When a factory whistle blows
• Twelve ___
• See 37-Across
• 'High' time
• Twelve, half of the time
• Deadline, sometimes
• Day divider
• Palindromic time
• Common lunch time
• Twelve
• See 67-Across
• Shootout time
• Day break?