How does Bradbury use the dates on which the story takes place as a form of foreshadowing?

Bradbury uses the dates on which the story takes place to foreshadow in two different ways. When the reader encounters the date "August 4" right after the "morning/mourning" pun, they should suspect that the family died in a bombing--which is later revealed to be the case. Second, because the Hiroshima and Nagasaki bombings took place over multiple days--August 6 and August 9--the reader wonders if there will be more bombings to come in the days after the story's close.