|Real name||Julian Gregory Day|
|Based in||Gotham City|
|Hair color||None (formerly brown)|
|Height||5 ft 9 in|
|Appearances||Arkham Asylum (mentioned only)|
|Voice actor||Maurice LaMarche|
Having a bizarre fixation on the calendar, Julian Day became Calendar Man, a serial killer who timed and thematically tied his murders and other crimes to certain holidays throughout the year. Much like the Riddler, he often left clues through which he could be caught.
Gotham City's hopes for a day off are often overshadowed by the knowledge that any major holiday is likely to be made dangerous by Calendar Man's actions.