Batman: Arkham City Calendar Man Easter Egg: The Secret Date
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Short answer: Arkham City’s best-hidden easter egg is a Calendar Man monologue that stayed undiscovered for three years. Set your console or PC clock to 13 December 2004, the day Rocksteady was founded, and visit Calendar Man: he says he has been there “from the beginning” and warns that the end of days is coming, read as a hint at Arkham Knight.
How to trigger it
- Change the system date of your Xbox 360, PS3 or PC to 13 December 2004.
- Start the game and visit Calendar Man in his cell.
- Listen to his special dialogue, which only plays on that date.
Other Arkham secrets: Arkham Asylum’s secret room, Arkham City’s Calendar Man easter egg and Arkham Knight’s Knightfall Protocol. More guides: all Batman: Arkham guides.
Sources
- Engadget: Three years later, Calendar Man reveals Arkham City easter egg
- Kotaku: It took three years for people to find this Arkham City easter egg
Last checked against sources: 10 November 2026.
