Unique Calendar Days. 437 rows fun holidays and observances for 2025 below is a listing of all major fun and quirky holidays. 211 rows enjoy our collection of the most weird, bizarre, and random american celebrations out there — like national cat herder day (dec 15), national cook for your pets day (nov 1), and—our favorite—national.
Where applicable, if the holiday or observance has an official website, we’ve linked to it. Founded in 2022 by national day calendar® and the security industry association (sia).