So there’s a lot of posts saying Augustus died on July 2nd, but that doesn’t fit with the text.
The beginning of Chapter 24 (pg 292) is 11 days AG (after Gus’s death).
On page 293, Hazel leaves early “the next day” so now we’re 12 days AG.
Chapter 25 (pg 301) begins with “I woke up the next morning…” so now we’re 13 days AG.
On page 304, Hazel says she “…commenced to refreshing around five in the morning.” So now we’re 14 days AG.
On page 305, Hazel’s mom says, “It’s July fourteenth, Hazel.”
So 14 days AG is July 14th, which means 1 day AG would have been July 1st; therefore, Augustus Waters died on June 30th, not July 2nd.