Here is an official 1994 Sonic calander. It's spiral bound at the top for easy page-flipping. It was only released in the UK for that year, and the art inside seems to be unique to the calendar. The length is 42cm and its 30cm wide. It has sonic snowboarding, eggman is his drill from sonic 2, Eggman's robots, Eggman trying to eat an easter egg, but sonic is inside it, Tails in a half pipe special stage, Sonic hang gliding, Sonic racing in a car, Sonic underwater as eggman shoots torpedos at him, Sonic and Tails flying, Sonic and Tails playing football while eggman is the goalkeeper, fireworks everywhere and Sonic and Tails celebrating (sort of) And sonic and Tails making a snowman eggman. 

In the gallary are the pages from the calendar. They appear to all be semi-original art, likely done by an air-brush artist. Some are clearly based on/altered stock arts (like Tails running, winking Sonic) but others seem original, for better or for worse. However, the whole set is pretty interesting to see. January shows they didn't grasp the concept of Sonic's spikes, he only has 2 visible despite being in 2/3 profile which, every other time he's in 2/3 profile, all 3 are always seen. Feb. has only badniks, which is neat to see. Cluckoid has somehow mobilized its' turret, and everything metallic is quite nicely rendered. March has only sortaeggman in his 'drill car' from Sonic 2, but the drill is tiny, as he fails to run rabbits over in his path. April is particularly awful, as...well just look at it. Mis-shapen empty eye-sockets, no neck at all, glove-less hands, mutant teeth, shrivelled 'foil egg' and odd Sonic toy inside. Sonic's race car is quite well done (artist clearly specialized in cars/machinery) September has swimmin' Sonic (which he couldnt do) The Tornado makes an appearance, and then there's some Soccer/Football confusion. Tails is in there, but tiny...is Eggman the goalie? What's going on with Sonic's spikes? November has fireworks, with Sonic & Tails holding sparklers in front of a detailed Eggman display. Then, December has Tails building an angry snowman (holding a magic stick??) while Sonic gets ready to throw a snow ball at it. (hard ot see because it's white, and behind the numbers) This is an interesting calander full of pretty much original things.