Related Clues:

• Zero hour for Will Kane, in a film
• Lunch time, maybe
• Thriving time
• When a factory whistle blows
• Twelve ___
• See 37-Across
• 'High' time
• Twelve, half of the time
• Upswing
• Deadline, sometimes
• 'Kapow!'
• Tiffin time
• [Sans warning!]
• Surge
• Day divider