"Nerdidays" were a thing celebrated for the first couple of years of the site, like holidays for nerds, commemorating occasions such as events in history, video game or TV anniversaries, and other such things. They were often used as a way of theming (minor) new feature or character style releases, but sometimes they were purely for fun.
- July 20, 2011: 42nd Anniversary of the Moon Landing
3 moon-themed character styles were released - August 19 2011: Eight years since Firefly was cancelled
The firefly-is-over emoticon was added - August 24 2011: Anniversary of Mount Vesuvius' eruption
Burnt Offerings and Phraetic Eruption character styles were released - November 20, 2011: 4th anniversary of the Mass Effect games
Darth_Angelus created a video to celebrate - December 21 2011: Birth of the Daleks
Short film by darth_angelus titled "Dungeonmaster of the Daleks" - October 16 2012: "Let Them Eat Cake" (219 years since Marie Antoinette was beheaded)
2 cake themed character styles and 2 death themed character styles were released
A "parade of characters" on the forums where people were invited to post their violent revolutionaries and their spoiled aristocratic characters
Lore Wiki » Traditions » Special Events » Nerdidays