Related Clues:

• An eternity
• Word with Dark or Middle
• Census statistics
• Millennia
• Billion-year increments
• Quite a stretch
• Eternities
• Has another birthday
• Subjects of white lies, sometimes
• Lotsa time
• Gets mellower
• What seems like forever
• Iron and Bronze, for two
• Piles on birthdays
• Golden and Bronze, e.g.