Harry Potter and the Prisoner of Azkaban
How we cite our quotes:
"I mean, you're good Hermione, but no one's that good. How're you supposed to be in three classes at once?"
"Don't be silly," said Hermione shortly. "Of course I won't be in three classes at once." (6.1.20-1)
Hermione's Time-Turner mystery is at the heart of the book, and especially at the heart of the its theme of time. So what does Hermione's Time-Turner tell us about time as a theme? Well, we'd argue, a whole lot. In this instance, at least, Ron asks how she's supposed to do three things at once. And the answer we learn is – not all that well. Hermione is totally burned out by the end of this novel, proving that there are 24 hours in each day for a reason.
Then he stood up, stretched, and checked the time on the luminous alarm clock on his bedside table.
It was one o'clock in the morning. Harry's stomach gave a funny jolt. He had been thirteen years old, without realizing it, for a whole hour. (1.24-25)
Harry has a very strong awareness of the passage of time here, since it's his birthday. It's significant that this scene pretty much kicks off the novel for us – time is an important aspect of this story from the get-go.
"I reckon he's lost track of time, being on the run," said Ron. "Didn't realize it was Halloween. Otherwise he'd have come bursting in here." (9.1.12)
Like any good mystery novel, this one leaves us clues. We get multiple clues about the "timing" of Sirius's attacks. Either Sirius has lost track of time, as Ron suggests, or he's the most inept villain ever (or he's not after Harry at all, but that's another story). Sirius actually has a freakishly accurate sense of time – when we finally meet him, it's clear that he's acutely aware of the time he has lost ,among other things.