|This event exists primarily or exclusively within the Sonic the Comic continuity.|
Information in this article may not be canonical to the storyline of the games or any other Sonic continuity.
Robotnik Day was the enforced "celebration" of Doctor Robotnik's complete conquest of Mobius, in an alternate reality in which Robotnik possessed complete omnipotence after absorbing the power of the Chaos Emeralds and Sonic the Hedgehog never existed.
For at least seventy years after taking power, Robotnik forced his citizens to celebrate the anniversary with parades, balloons and banners, but relished their unending misery. Reality was eventually restored to normal and Robotnik's powers completely taken away.