math_fact: 1504 is the number of anisohedral 21-iamonds.
trivia: 1504 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: February 12th is the day in 2004 that the city of San Francisco, California begins issuing marriage licenses to same-sex couples in response to a directive from Mayor Gavin Newsom.