Possible Clues:

• Solstice time: Abbr.
• End-of-the-year mo.
• 1998 Compaq acquisition
• Kwanzaa mo.
• End of the yr.
• Sagittarian's mo., probably
• Nog mo.
• Four mos. after 20-Down
• Mo. Kwanzaa begins
• Busy month for the USPS