The argument you presented is known as the cosmological argument, which suggests that the existence of time and the universe requires a divine creator. However, it's important to note that this argument is not specific to atheism; it is often used as a philosophical argument for the existence of a god in general.
While the cosmological argument is one way of interpreting the origins of the universe, it's not universally accepted or conclusive. There are alternative scientific theories, such as the cyclic model or the multiverse hypothesis, which propose different explanations for the existence of the universe and the concept of time.
Furthermore, it's worth mentioning that atheism is simply the lack of belief in a god or gods. Atheists can hold a variety of views on the origin of the universe and the nature of time. Some may adhere to scientific explanations, while others may simply say they don't know or consider the question outside the realm of current knowledge.
In any case, philosophical arguments like the cosmological argument are subject to debate, and people may have differing opinions and interpretations. The existence of time does not necessarily imply the existence of a god, as there can be alternative explanations or unanswered questions about the nature of time itself.