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
• Tiffin time
• Top of a clock dial
• When shadows disappear
• Sundial letters
• Day divider
• See 36-Across
• Palindromic time