Yup, like Emberfly linked, rosierjay organized a collaboration calendar. It was no cost for a digital copy, and just the price of printing/shipping for a physical one, though I don't know if she's still offering physical ones or not. It was a lot of fun and I loved everyone's seasonal ponies. I'm hoping we can organize one again this year.
Ponycake, if you don't mind PMing your email, I can forward the digital calendar to you. It's a big PDF so I don't think I can send it through the arena.