A nice calendar I can hang on my wall with the in game year would be wonderful. If it doubled as a conventional calendar, great, but having something like this would be wonderful to hang up in the game room.
You've got SO MUCH art you could use for it each year, and AND you could sneak in promotions for book release dates on it. Marvel does this for their comic books.
It would make my life so much easier, and you could release a new one each year!
This is an awesome idea!
Add me to the vote here!
In the meantime, there's a really good alternative in Dungeonetics.
Printable Golarion Calendar
You can set the year, it has holidays marked as well.
No art, but you could pretty easily make something cool with binder sheets. And once they're in binder sheets... BOOM! Dry erase calendar!
I was planning on printing one out for 4707 and having it in my game room for my ROTR campaign. I hadn't thought about art for it, but I'll probably add some that relates to the Deity which the month is named after.