Also it seems to happen randomly, I have multiple saves and sometimes the sleep option disappeared, sometimes it doesn't no matter what I do. There's probably a factor with me changing my companions anatomy as well
For me the same kind of thing happend,. I have to add to it says for the time that it is undefined. I.e "It is Friday, [undefined], Day 208. Boloyam". Got it to work again. When you have it ,I was able to masturbate and progress the time again. Only happens that noticed it when on the new continent.