I think (and its my opinion only), you should get background for your calendar. For the snowy one, its looks just ok (more than ok, its amazing) but still, always the same grey font seems to fade the general interest in the image. I found the snail rather cool ( I want them D: ), and so think its OK to stay with no background, when it come to only a photo. But think of it when its a pic that you see for a complete month, most every days... It could extend the enjoyement of it.
hehe, his face reminds me of a walrus sorry, whenever I comment on your snails it seems like I'm always saying something like "it reminds me of.." "that looks like.." instead of anything actually.. I dunno... O_o but if it's bugging you, I can stop..