ABSTRACT. I argue for four modestly verificationist theses about certain concepts crucial in this area, such as "period" and "instant", and that in consequence of these theses the only coherent account which can be given of the Universe having/not having a beginning is in terms of its existence being preceded by/not preceded by a period of empty time. It follows that it is not logically possible for time to have a beginning, and that physical cosmology could never show us that the Universe had no beginning, but it could show us that the Universe did have a beginning.