What is the author's purpose in naming several of the novel's chapters after days of the week?

Van Meter titles four chapters with the name of a weekday — specifically, “Thursday,” “Friday,” “Saturday,” and “Sunday.” This group of chapters focuses on the four days when Mom visits Evie immediately before her wedding with Liam. “Thursday” is the very first chapter in the novel, while “Sunday” is the very last chapter in the novel, emphasizing this group’s importance within the novel.