Yes. The creation of things was in the beginning of time because things are said to be created in the beginning of time, not as if the beginning of time were a measure of creation, but because together with time heaven and earth were created.
Nothing is made except as it exists. But nothing exists of time except "now." Hence time cannot be made except according to some "now"; not because in the first "now" is time, but because from it time begins.
The words of Genesis, "In the beginning God created heaven and earth," are expounded in a threefold sense in order to exclude three errors.
(1) For some said that the world always was, and that time had no beginning; and to exclude this the words "In the beginning" are expounded--viz. "of time."
(2) And some said that there are two principles of creation, one of good things and the other of evil things, against which "In the beginning" is expounded--"in the Son." For as the efficient principle is appropriated to the Father by reason of power, so the exemplar principle is appropriated to the Son by reason of wisdom, in order that, as it is said (Psalm 103:24), "Thou hast made all things in wisdom," it may be understood that God made all things in the beginning--that is, in the Son; according to the word of the Apostle (Colossians 1:16), "In Him"--viz. the Son--"were created all things."
(3) But others said that corporeal things were created by God through the medium of spiritual creation; and to exclude this it is expounded thus: "In the beginning"--i.e. before all things--"God created heaven and earth."
For four things are stated to be created together--viz. the empyrean heaven, corporeal matter (by which is meant the earth), time, and the angelic nature.