Related Clues:

• Place for change
• 8:00-8:30, e.g., on a schedule
• Compartment
• Opening for a mail carrier
• Narrow opening
• Impel
• Prez backup
• Part of a jukebox
• Substitute
• Assistant
• Prez's #2
• Stimulus
• Machine with a hole in it
• *Opening ... machine ... schedule
• Coin opening