In fahrenheit 451 how does bradbury indicate that a week has passed

In fahrenheit 451, Bradbury indicate that a week has passed because he counts the days that passed and makes a space in between the paragraph and the paragraph before it. The numerals 451 represent the degree at which books burn. So the asnwer in this question is that bradbury counts the days that passed and makes a space in between the paragraph and the paragraph before it.