Possible Clues:

• Dec. 25 or Jan. 1
• Christmas, e.g.: Abbr.
• Jan. 1 or Dec. 25, e.g
• Jul. 4th, e.g.
• Jan. 1 or Feb. 14, e.g.
• Jan. 1, e.g.
• Dec. 25, e.g.
• Aug. doesn't have one
• Xmas, for one
• Jan. 1st, e.g.