Pottermore and J. K. Rowling have created a calendar for 2016. Each month contains a different moment/artwork, as well as various holidays and some birth dates. The link to the calendar was posted on their official Pottermore site on Facebook, and the calendar itself can be downloaded as a PDF or a zip file. As far as I know, there are no hard copies available.
If anyone would like the link, feel free to message me.