Roots Day 
Many people are uninterested in where their ancestors came from…until they start researching the topic deeper. And then suddenly it turns out that their family history was a long and fascinating one, and they become obsessed with finding out everything possible about where their forefather come from that they talk the ear off of anyone even remotely interested. Maybe they were related to a famous person who made a significant discovery or took part in an important battle or other historical event? People have been migrating to all different parts of the world for hundreds of years in search of a better place to live, worship and raise their families, motivated by everything from religious prosecution to hunger and poverty in their own countries, to taking part in great wars that made our world what it is today, so it stands to reason that everyone would find something interesting about their own family history. Your parents, grandparents, etc. and their decisions are what made you who you are today, and had they made different decisions than they did, then it would not have only been their lives that would have ended up affected. Many times questions that have plagued us our entire lives can be answered with some solid family history research, and even spending just a few hours might reveal some valuable information.
https://www.daysoftheyear.com/days/roots-day/
Festivus 
has a very odd and amusing start. It was conceived by author and editor Daniel O’Keefe and was celebrated as early back as 1966 by him and his family. But, how did Festivus become so popular if it was just a family tradition? To find that out, we must move forward in time to an episode of the famous television show Seinfeld. While the holiday is extremely popular among people today, the first time Festivus was mentioned in American culture was in the episode of Seinfeld called “The Strike”, but there’s more to the name of Festivus than just a referenced television episode, right? Indeed there is, because the word “festive” is derived from the Latin word “Festivus”. Sound familiar? It should. Festivus is an adjective meaning “excellent, jovial, and lively” which in turn derives from Festus, which means “joyous; holiday; feast day”. Plus, it brings one to think, maybe Festivus is to prove that we as humans don’t need material objects to be happy on a holiday, but all we really need is excellent company, jovial attitudes, and lively music to make the holidays the best we could have.
https://www.daysoftheyear.com/days/festivus/
http://www.famousbirthdays.com/december23.html