Horses have the same birthday (Happy New Year!)

That is the custom — every horse has the same birthday, Jan. 1. Like all things calendrical, this is a human convention. When it comes to equine conventions, I know enough to notice some of the simpler forms of precedence: who goes first through a gate, who gets to the grain feeder ahead of the others. But I can report that the horses make no fuss about their common birthday or the coming of the new year. Tonight, like any other, they will be standing, dozing on their feet, ears tipping back and forth at the slightest of sounds. (nytimes)