Related Clues:

• Diary duration
• ''Newsweek'' cover number
• Demographic datum
• Fossil feature
• Life time
• Demographics datum
• Lunar or leap, e.g.
• Part of a century
• Oenophile's concern
• ID datum
• With 57-Down, ancient
• Time division
• Car registration datum
• Trip around the sun
• It ends with 42-Across