|First appearance||"A Farewell to Arms" (7ACV02)|
The Martian calendar is an ancient calendar discovered by Dr. Amy Wong in 3012 (7ACV02). Due to it being written in Martian, only natives of Mars such as Amy could decipher it, and even she experienced difficulty in doing so. It appears to be a doomsday calendar, predicting a number of disasters such as fires, earthquakes and "sharksplosions", followed by the world ending. When news of the calendar's predictions was known, typical end-of-the-world chaos took place on Earth, such as mass suicide, crime sprees, and people suddenly sitting back callously, living their lives to the fullest before their imminent death.
An ancient Martian stone spaceship, found at the same site the calendar was found, was used to evacuate 30,000 Earthicans chosen by the Contrabulous Choosematron to Mars. It was there that Singing Wind revealed that Amy had not translated the calendar completely, and that it was actually a warning by the ancient Martians to the Earthicans not to go to Mars, as it was Mars and not Earth that would be destroyed.