Related Clues:

• Part of Y2K
• Orbital period
• Revolutionary period?
• Revolution time
• Whisky or wine datum
• 669 Martian days
• The '70s, e.g.
• Century segment
• Revolution time?
• Spring, summer, fall and winter
• Summer to summer
• 2006, e.g.
• Leap __
• 2008, e.g.
• Period of revolution?