Haha. I’m sorry if the terminology is catching you out. It’s not epoch time that floats. Epoch time is an inalienable absolute (at least in theory). However actual cosmological and time as perceived by humans does drift wrt to epoch time. Which of these is right is a philosophical discussion but at the present instant they do indeed converge and so epoch time between now and some time in the early 1960s is “the correctest” from a systems perspective.