Related Clues:

• Zero hour for Will Kane, in a film
• Lunch time, maybe
• When a factory whistle blows
• Twelve ___
• See 37-Across
• Rest after almuerzo
• 'High' time
• Twelve, half of the time
• Nap
• Deadline, sometimes
• Snooze
• Tiffin time
• Day divider
• Palindromic time
• Sleep time