Height: 6'0" (183cm)
Weight: 185 lbs
Jason "Dooms" Day (born May 19, 1981) is a Canadian mixed martial arts fighter born in Lethbridge, Alberta, Canada, and has fought for several MMA associations, including Ultimate Fighting Championship, Rumble in the Cage, King of the Cage, and many others. He is also the former TKO Middleweight champion.
He is one of the few practitioners of the Eddie Bravo "Rubber Guard" system in Mixed Martial Arts, in which a fighter can avoid taking heavy damage when fighting from his back, by using his legs and arms to hold his opponent very close to him in order to stifle his attacks. This was demonstrated best in his fight against Alan Belcher in UFC 83
Day fought his second fight in the UFC on June 7th, 2008 at UFC 85 in London. His opponent was Michael Bisping who defeated Day in the first round.