Day of the Ninja In 2003, the creators of Ninja Burger declared that December 5 would be celebrated as Day of the Ninja. On this day, people are encouraged to dress as ninja, engage in ninja-related activities, and spread information of ninja online. December 5 was originally chosen because December 5, 2003 marked the release of Tom Cruise's film The Last Samurai (which featured a scene where samurai battled ninja). Since then the focus has shifted towards the more familiar Pirates versus Ninja conflict, and the day has served as a virtual counterpoint to International Talk Like a Pirate Day.
Another site, ninjaday.org, has independently declared December 5 as International Creep Like a Ninja Day. Other possible names include Stalk Like a Ninja Day, Sneak Like a Ninja Day, Move Like a Ninja Day, or simply Ninja Day.