Related Clues:

• Go around in circles
• Period of time
• Wine connoisseur's concern
• '00, e.g.
• Subscription length, often
• Round trip?
• See 54-Across
• Comet's path
• Junior, for one
• 2001, e.g.
• Sphere
• Birthday-to-birthday span
• 2000, for one
• With 28-Across, late December
• Time period