My girl and i had lunch there today, and as we were paying, i mentioned the panic caused a couple weeks ago when they were closed for a few days...
the woman i spoke to seem bewildered that so many people cared, and almost oblivious to the fact that the Yak is one of the best restaurants in the City.
anyway - as it turns out, it was the Tibetan New Year, and since most of the staff is Tibetan, they were closed. maybe someone mentioned this already, but i couldn't remember - anyway, that being said, expect this to happen once a year about this time. :o)