Related Clues:

• Jr. and sr., e.g.
• Millennium fractions (Abbr.)
• 56-Across and others
• Mos. upon mos.
• Abbr. in old letter sign-offs
• Model information: Abbr.
• Sr. and jr.
• Cen fractions.
• Cen. parts
• Yr. parts
• Abbr. for seasons played
• Time line markings: Abbr.
• Calendar pp.
• Loan periods: Abbr.
• Mos. add up to them