This has been bothering me for a while. If you have a modern very accurate moonphase, say accurate to within 122.6 years like a Lange or something even more accurate, and say you bought it secondhand and you don't know when the last time it was wound, and the moonphase is off, how do you set it? How do you find out where in the 122.6 year cycle you are? If you set it ahead, do you need to let it wind down to catch up? What if it's accurate to within 1,000 years, or 5,000, is that just impossible to set properly?

I am aware that perhaps this is a stupid question, but please humor me.