I can provide you with some information about the perspective of atheists on the concept of nonexistence after death.
Atheists generally hold the view that there is no existence or consciousness after death. Since atheism is a broad term encompassing a range of perspectives, atheists may have different interpretations or beliefs about what happens after death, but the absence of an afterlife or continued existence is a common theme.
From an atheistic standpoint, the end of consciousness and existence occurs at the point of death, and there is no belief in an immortal soul or an afterlife where an individual's consciousness would continue. According to this perspective, there is no specific duration of nonexistence or a subsequent starting point for existence after death.
It's important to note that individual atheists may have diverse beliefs and interpretations, and their perspectives on what happens after death can vary. Atheism itself is solely a lack of belief in gods or deities and does not provide a definitive answer regarding the nature of consciousness or existence after death.