Good that tokeweed has mentioned Pride FC, as they were the one who loved to have events on December 31.
I remember like it was yesterday. It is 23:50, I am sitting around the new years table (celebration of a new year on Dec 31 is a bigger holiday than xmas in our country) with my family, the president is about to give his speech, summarize everything we had this year and etc, people about to drink Champaign and run outside to fire fireworks, everyone are happy. Happy except me, because I want to switch TV to sports channel and watch Fedor "The last Emperor" Emelianenko fight
https://en.wikipedia.org/wiki/Fedor_Emelianenko - take a look yourself. Go to his record section, press ctrl+f and type 31 December. While everyone were eating salads, meatballs, drinking, opening presents, he has been fighting 7 times on the last day of the year. Crazy Asians
I wonder how making a fight on the 31st would be fair to the fighters? they are also people who have family and who have the right to be with their families to spend the 31st together, they shouldn't be greedy to let the family spend the 31st without them just because they want to fight and earn money, when they stay sick people will be in bed and will need the family to take care of them, their money doesn't have the legs and brains to take care of them
also people on the 31st travel and others are just focused on spending the day resting and doing activities with their family and friends, but most of the time they are not activities of watching or betting on fights, I think that even the casinos or the promoters of fights would be at a loss because few people would watch the fight on the 31st, it would not be advantageous for any fight promoter to put a fight on the 31st