At the end of The Prisoner of Azkaban, Harry and Hermione travel back in time to save Sirius (and as it turns out, Buckbeak) and escape the Dementors.

If this is a legitimate option for saving people, why don't they ever use it again? If they can use it to save Sirius in The Prisoner of Azkaban, why can't they use it to save him when he dies in The Order of the Phoenix? For that matter, why can't they go back to the beginning and kill Tom Riddle before he becomes Voldemort?

The only thing I can think of is that in The Prisoner of Azkaban, maybe they use the Time Turner before Sirius is given to the Dementors, and so they're not actually saving him from something that already happened; they're altering a series of events that they know will lead up to him being handed over to the Dementors. Is that how time travel works in Harry Potter land? That is, you can't alter something as definitive as death (or a Dementor's kiss), but you can alter other events that have occurred and consequently prevent a death that you know will occur?


12 Answers 12


From what I remember about the books and the films, Hermione only gets given the Time Turner device in her third year at Hogwarts. She was given it, with the permission of the Ministry of Magic, so that she could attend two sets of lessons at once.

In this link, you can see that she stated that the pressure of using it to do twice as much work became too stressful, so she returned the device to the ministry. In the following year, all the devices were destroyed during the battle at the ministry, so it was not possible to use the device again. I am therefore guessing that the art of creating such a device was lost in the years since they were first made.

  • 18
    Good point. I remembered that Hermione didn't have the Time Turner until the third year, but it seems a little odd that Dumbledore would give it to her in order to take classes, but not give it to Harry (or use it himself) in order to save lives. Also - now that you mention it I remember that in the books, the Time Turners were destroyed during the battle at the Ministry. But I'm not sure they pointed that out in the movie, did they? If not, they should have!
    – Lauren
    Commented Dec 2, 2011 at 14:32
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    You raise an interesting point. If they are so rare and can not be reproduced, why would Dumbledore give such a thing to Hermione just for taking more classes? There would be so much more useful things to do. Then again, as Dumbledore said, his greatest wish was a pair of warm socks. He of all people would know the danger of using very powerful things to do something you think is good. Instead of wishing for more power to make the world better, and instead of using the Time Turner to destroy Voldie, he used it for 'good' on a smaller scale. Commented Dec 5, 2011 at 9:33
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    I think that Rowling didn't really want to play with time, but it was a path she felt was necessary for the direction of the story. As such, there are going to be inconsistencies and open questions, because time travel offers an unparalleled scope, and it would be difficult, impractical and boring for the reader if they were all tied up neatly.
    – Codemwnci
    Commented Dec 8, 2011 at 18:03
  • All the requisite ability is available to them to reconstruct time travel had they the wit to find it. But in the era it was set, the greatest of our scientists if put to the question might not realize they know all the pieces even given a technique that can construct any mundane object.
    – Joshua
    Commented Feb 1, 2018 at 16:14
  • "I am therefore guessing that the art of creating such a device was lost in the years since they were first made." That seems to be reasonable. It sure would be problematic story-telling if it were established that people can just make new ones willy-nilly. Commented Jun 26, 2021 at 2:58

I'm not going to repeat the excellent plot oriented answers - but its my opinion that JKR probably realized that freely available and controllable time travel can critically damage your ability to make a problem that cannot be simply resolved by the protagonist. Magic itself has that problem too - but at least she can put limits on the magic and the fact that other characters in the story have magic too which cancels out some of the power that gives Harry & co.

This is exactly why (most) of the stories that include time travel that I can think of involve plot points to make it unpredictable or uncontrollable or simply hard to do:

  • Back to the Future (1.21 gigawatts of power required to operate the Flux Capacitor)
  • Dr. Who (the Tardis navigation is broken and hard to control, and for one whole period was grounded entirely)
  • Star Trek (time travel always happens through some accident or external issue - though magically they always get to return ok)
  • The Time Tunnel (I seem to recall that there is an accident with it)
  • The Time Machine (he passes out when using it and ends up going too far)
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    Dr. Who also has this idea of "fixed points in time", that cannot be altered.
    – oers
    Commented May 10, 2012 at 8:24
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    @oers Fixed points are a rather new invention in Dr. Who though, IIRC.
    – Michael
    Commented Jul 17, 2015 at 18:45
  • Yeah, they seem to have fixed the Tardis navigation issues in the new Dr. Who - so they would have to introduce some other barrier to them using it to solve every problem they have.
    – iandotkelly
    Commented Jun 23, 2021 at 16:26

From reading the books I'd say that in a sense a Time-Turner can't really be used to change the past at all. In The Prisoner of Azkaban, Harry and Hermione use the Time-Turner around midnight to travel back three hours in time, endeavoring to save Sirius and Buckbeak. However, everything they do in these three hours has already happened:

  • At the end of Chapter 16, there's "the unmistakable swish and thud of an axe" (followed by Hagrid's howling). Later we learn that this was not the executioner killing Buckbeak, but the executioner swinging his axe into the fence in anger.

  • At the end of Chapter 20, Harry, Hermione and Sirius are saved from the dementors by the Patronus that the back-in-time Harry conjured, and the "real" Harry sees his "future" self patting the Patronus (believing that he sees his father).

  • Only in Chapter 21 they use the Time-Turner. I'd say they have to use it since they had already taken influence on the past, as described in the previous two bullet points – their travelling back in time had already happened.

Thus, the answer to your question is: When you use a Time-Turner, you can alter only events that you have no definitive knowledge of. (Everything Harry and Hermione do is 100% consistent with what they had already experienced first-hand.) In particular, you can't go back to the beginning and kill Tom Riddle before he becomes Voldemort.

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    While the examples from the book may be sound, this whole question is about the movie. If this same question was asked on lit.se, then this would be a good answer, but this is about the movie, and as far as i can remember, no in-movie explanation was ever given about this.
    – Tablemaker
    Commented Feb 13, 2012 at 15:59
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    @Tyler: Yeah, you're right. That's why I started my answer with "from reading the books". I just thought the answer might still help. Commented Feb 13, 2012 at 16:02
  • I have no doubt it helps with the answer and the books themselves say flat out why. I'm just trying to poke around and get people's reactions to answers to adaptations using the source material, rather than the movie itself :)
    – Tablemaker
    Commented Feb 14, 2012 at 4:45
  • @Tyler: Right, that's good. Then here's another one for you. That's the answer I was just going to post :-) Commented Feb 14, 2012 at 7:45

I can not recall exactly where or when but I vividly remember that Dumbledore once told Harry that playing with time can be a very dangerous act and it can trap the time abuser in something like a Time Loop (for whatever it is!).

But in my own opinion time traveling is one those matters that if not dealt with correctly and thoroughly can become one of those weak points of the story and obviously it is a weak point in the Harry Potter series.

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    That last bit of course is very true, from the storytelling-perspective. It ruined (to me) lots of movies, tv series and books. But it doesn't explain it from a point of view inside the Potterverse. Commented Dec 5, 2011 at 9:36
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    Maybe you had this piece in mind, from Chapter 21, Book 3? Hermione says "Exactly! You wouldn't understand, you might even attack yourself! Don't you see? Professor McGonagall told me what awful things have happened when wizards have meddled with time ... Loads of them ended up killing their past or future selves by mistake!" Commented Feb 13, 2012 at 13:10
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    I can not recall exactly where or when but I vividly remember that Dumbledore once told Harry that playing with time can be a very dangerous act and it can trap the time abuser in something like a Time Loop (for whatever it is!). this is not true at all. Commented Jul 7, 2017 at 11:35
  • While some people don't like it, The Cursed Child gets back to time travel and either many alternate realities are created or the characters discover they exist and pass through them, "believing" that they need to change something back. TPOA shows the viewers that these events already happened and despite DD's words HP may just have grandfather's paradox... Commented Dec 23, 2019 at 17:30

I believe that the time tuner cannot surpass reminding over a day. On a replica timer tuner I own it has inscribed on it: "I count the hours, every one. Yet have I to outrun the sun." I think this means that the time tuner doesn't have the power to go back a day's time. All magic has its limits right?


If just say Harry had travelled back to when Tom Riddle was young and killed him, Harry would have no way of getting back to the present time as it appears the Time Turner only allows people to go back and no forward. This would result in Harry being old by the time he is supposed to be in Hogwarts.

So if this was to work then one individual would have to sacrifice their life in the present time for a life in the past.

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    That's a good point. It's also worth suggesting that if it's 1 turn per hour and the idea is to go back and stop Tom Riddle when he's a boy, lets see, If that requires travelling back 30 years 30 x 365 x 24. I imagine the Time Turner would break before it lets the user turn it over a quarter of a million times.
    – userLTK
    Commented Jun 19, 2017 at 9:47
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    @userLTK Not to mention, so would be the user's wrist.. ;)
    – CCCC
    Commented Aug 22, 2019 at 8:26

Here's a practical answer.

In Prisoner of Azkaban, Harry and Hermione move the time turner three times to go three hours in the past.

By the time Tom Riddle turned into Voldemort, he was probably 18. So anyone who wants to kill Voldemort would have to move the time turner for 10*365*24 times, in order to kill Tom Riddle who wasn't powerful at all when he was 8.

Which, honestly, sounds like a lot of effort.


Here's a hypothesis since it is not stated in the book. I believe even with magic a person cannot go back in time before their birth. Also may be the time turner is simply a magical object that isn't as powerful enough to move far back in time.

But that's just hypothesis, only real facts are that it has mental effects on the user. Like Hermione getting stressed or Dumbledore warning that the wearer cannot let the past self-see their future counterpart otherwise they can get crazy.


They were destroyed.

In the scene in the Department of Ministries in OotP we hear that they are destroyed (this is from the book).

The baby-headed Death Eater was screaming and banging into things, toppling grandfather clocks and overturning desks, bawling and confused, while the glass cabinet that Harry now suspected had contained Time-Turners continued to fall, shatter, and repair itself on the wall behind them.

- Harry Potter and the Order of the Phoenix, Chapter 35 (Beyond the Veil)

Later it is made apparent that they did indeed destroy all of the Time-Turners.

Ar, I always knew yeh’d find it hard ter squeeze me inter yeh timetables,” he said gruffly, pouring them more tea. “Even if yeh applied fer Time-Turners—”

“We couldn’t have done,” said Hermione. “We smashed the entire stock of Ministry Time-Turners when we were there in the summer. It was in the Daily Prophet.”

- Harry Potter and the Half-Blood Prince, Chapter 11 (Hermione’s Helping Hand)

So they couldn't have used the time turner even if they wanted to.


Going by the other answer that says it can't outrun the sun, so, no more than 24 hours. There's still the question, why didn't they go back and save Sirius from his death. Lets assume that it was possible, why wasn't it done?

The cheap answer is that they didn't have the time turner. It was presumably locked away in Hogwarts for safe keeping and not easily gotten to, but lets assume that Dumbledore could have gotten hold of it, so hypothetically, Harry has the Time Turner, with Dumbledore's consent. Why not save Sirius?

In the books, Hermione told Harry - "Terrible things happen to wizards who mess with time" and Dumbledore told Hermione - "You know the rules" - so, there are rules and consequences. That much is clear. I think there was also a "let nobody see you" warning in there as one of the rules.

One problem that immediately stands out is if Sirius isn't part of the rescue party, that is, if they warn him not to go and he doesn't, maybe somebody else dies. Maybe Harry dies. At the very best, there would be one less person for the rescue, with at least a fair chance of somebody else dying.

When warned of his death, Sirius might likely have said - "I don't care, Harry is what matters". Warning him might have done little, except perhaps kept his defences up when Bellatrix was near.

There's also the "let nobody see you" problem. How do they go back in time, tell Sirius not to go and have nobody say to him - "Sirius, why aren't you coming? - Harry needs you".

When Sirius and Buckbeak were rescued in the previous book, Buckbeak was chained to a post but unwatched. Sirius was locked-up in the tower up but unwatched. Rescuing them could be done un-seen. That's more difficult if someone is part of a rescue mission.

In theory, Harry could have gone back to warn himself not to go, but again that breaks the rules. "Terrible things happen to wizards who mess with time."

It seems probable that Harry might ask for the time turner, at least to Hermione if not Dumbledore, because that's who he was, more heart than sense and "save him" would have been the first thing on his mind. Either one of those two would have recognized the situation was one where the time turner would be a terrible idea, as most situations you'd want to reverse would be. Rare situations where the rescuee is alone, and location is known within 24 hours - maybe and even then, using it is risky (and probably illegal).


It's obviously not possible because even if they killed Voldemort when he was Tom riddle in the past, He would live on in the present time because the time turner only alters the events never changes the outcome. If we consider Sirius being kissed by the Dementors as in the movies, Harry never did anything to alter that. He was kissed a second time too. But Harry cast the Patronus charm in such a way that it matched exactly as he saw it in the past.

Tom riddle couldn't be killed as a teenager. This is because either Harry or Hermione wouldn't be born back then. Moreover they would have to live their lives until the present time which must be at least 50 years if we go by the mechanism of time travelling.

Regarding why JK Rowling did not use time turners any further than Prisoner of Azkaban I can only conjectured that it was a plot device designed to show how dangerous time travelling can be. Hermione herself said that people ended up killing the present form of their selves back in the past thinking some black magic was going on. Also Hermione was pretty stressed after using the time Turner repeatedly. She and Harry ran the risk of getting caught while rescuing buck beak and Sirius.

Even if they used it as you stated, there wouldn't have been any story. Rowling is the Queen of Harry Potter universe and its all at the mercy of her prejudices.


While other answers provide good logic for how time travel perhaps works in 'The Prisoner of Azkaban', there may be more insight into the matter...

While some fans have rejected as canon for various reasons,including some inconsistencies, Harry Potter and the Cursed Child revisits time travel (and Time Turners) again, where either the main Harry Potter timeline exists along side several parallel universes/timelines or alternate realities can in fact be made with devastating results! (and what I mean is that is evident that alternate timelines exist from time traveling, but they do so without erasing already existing ones, as characters from the future-present main timeline are able to stop the time travelers who are coming to exist in alternate realities they have seemingly created!)

'The Curse Child' features one son of Harry Potter's, the daughter of Tom Riddle/Voldamort, and the son of Draco Malfoy, as they attempt to change events save Cedric Dickory, although Delphi has an alliterative motive in wanting to save her father...

Delphi then reveals her true self. She does not wish to destroy the time-turner. Her plan is to travel to the past and stop Voldemort from ever dying. She wants to create a Dark age. She breaks their wands and kills a prefect named Craig who was sent to look for them. Delphi then makes Albus and Scorpius travel in time with her to the third task.

But ultimately when Delphi can not get her father to accept whom she is,(But Harry is playing a trick on her) Harry arrives in the past and after a duel, he explains that you can't change the past...

It works for a moment. Delphi pleads with Voldemort/Harry to accept her, revealing she is the daughter of Voldemort and Bellatrix Lestrange born at Malfoy Manor before the Battle of Hogwarts. Harry pretends to accept her although the spell making him look like Voldemort fades and she gets upset. Delphi and Harry duel until his friends and Albus help him. Delphi is stopped and says she only wanted to know her father. Harry tells her he understands how it feels to have no parents but they cannot change the past.

The real Voldemort then arrives to kill the Potters and Delphi tries to call him. Hermione and Draco stop her. Harry decides to stay and watch his parents die in the hope it will bring closure and Albus stays with him. Hagrid then appears to pick up Harry as a baby to go to the Dursleys. They return to the present, where Delphi is sent to Azkaban.

But what one might take away from this play, is that one might of been able to actually change something, otherwise Harry would not of had to interfere or send "a perfect" (indicating there are more mechanics to time travel than first explained)--there surely must be some consequences, otherwise it wouldn't of mattered too much what Delphi attempted to do...

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