Calendar Man is an enemy of Batman.
Calendar Man is an enemy of Batman obsessed with dates, who commits crimes according to the calendar based on significant holidays. Originally depicted as wearing a series of garish costumes depending on the date, he developed into a more serious look during The Long Halloween with a tattoo of the months surrounding his skull. Diagnosed as clinically insane, he is a resident of Arkham Asylum. He has been a member of the Misfits and the Time Foes.
When Superman and the Justice League arrive to move all the Arkham inmates to a more secure location, only to be stopped by Batman and Nightwing, the Calendar Man is frustrated when Robin does not recognize him, and attempts to remind Wonder Woman of an encounter they had where she broke one of his ribs as she thwarted a crime he was attempting to commit, and becomes despondant when she only glares at him.
Calendar Man is next fights Nightwing, but is easily held back by the hero. Calendar Man is last seen among the inmates who sorrowfully watch Batman carry Nightwing's body out of the Asylum.
Calender Man was seen as one of the prisoners who escaped from The Trench.
Injustice 2 Comic
Calendar Man was seen as a member of the Suicide Squad. He is almost killed but the bomb in his head malfunctioned.
Powers and Abilities
The Calendar Man, while being criminally insane, is still a genius and expert at staging crimes related to holidays.
The Calendar Man is a tall, overweight, bald man with the abbreviations of the months tattooed around his head. He wears an orange Arkham Asylum jumpsuit.