5. Haunted Mansion Fashion

During this event Disneyland's Haunted Mansion fills with fashionable boys and ghouls. And there's tons of style in the ride to be inspired by — from proper suits on the men featured in the stretching portraits to the eerie damask wallpaper that's a perfect design for a dress or a tie. More information about this event will be released on its Facebook page.

6. Steam Day

Grab your cogs, gears and aviator goggles — Steam Day celebrates "steampunk," that science fiction genre that embraces steam-powered machinery over Tomorrowland tech. Steampunk has been featured in Disney movies like "20,000 Leagues Under the Sea" and "Atlantis: The Lost Empire," and interestingly, steampunk themes and an airship ride were almost added to Disneyland in the 1970s, but the idea never made it off the ground. The event has continued to expand since it began in 2012, and this year, fans are set to gather in November. This group prefers to ride on the Disneyland Railroad and the King Arthur Carrousel, and they also participate in a Steamhunt (steampunk scavenger hunt) that starts at King Arthur's Sword. More information, including the specific date of this year's event can be found on Steam Day's Facebook page or website. 

7. Galliday

Hundreds and hundreds of Whovians have been descending on Disneyland for periodic events to celebrate their love of sci-fi institution Doctor Who. "Galliday" is a play on The Doctor's home planet, Gallifrey, .and previous events have played on the history of the show with names like "The Oncoming Storm," "The Next Regeneration" and "Jelly Baby Jamboree" (which refers to the Fourth Doctor's favorite snack). Whovians dress up like their favorite characters or in fan T-shirts, search for items to photograph in scavenger hunts and can even participate in Whovian Speed Dating at Trader Sam's Enchanted Tiki Bar! For more information about this event, click here. 

8. Pinup Parade in the Park

This event is similar to Dapper Days, where participants dress up in vintage-inspired outfits, but this one is more focused on the glamorous bombshell pinup look of the 1940s to 1960s. (Think Minnie Mouse, with her cute dresses, matching bows and shoes.) Pinup Girl Clothing, a boutique with a huge online following, hosts the events, which draw hundreds of well-dressed women to Disneyland for goodie bags, trivia and group photos. The parades are typically held twice a year (one was in October 2015 and the last was in April 2016), but a date for the next one hasn't been announced yet. You can watch Pinup Girl Clothing's Facebook page for event updates and fashion inspiration.

Most of these events are free with park admission. (Some events outside the parks require separate tickets.) And not only do you get to see Disneyland and Walt Disney World in a whole new light, you get to do it with tons of people who have the same unique interests that you do! The group rides, dinners and meet-ups are also perfect for solo Disney travelers, because you don't actually have to explore the parks by yourself and you're likely to meet a lot of interesting people. Have you ever participated in one of these unofficial days? Which one would you most like to attend? Sound off in the comments below!