You don't need to go back in time to 2004 to rewatch Harry Potter and the Prisoner of Azkaban, the franchise's most magical, whimsical, and fun entry to date. Luckily, you can stream all the Harry Potter movies online, but the chances are that you already keep the collection as well-guarded as you would Horcruxes (if you had any reason to possess such things). But if, for example, you needed to rescue a loyal hippogriff, or save a friend from having the life sucked out of them, or do pretty much anything that requires you to undo something terrible and make life a bit easier, then time travel would come in very handy. This begs to question why the Time-Turner isn't used again in the Harry Potter series.
The third entry Harry Potter and the Prisoner of Azkaban served as something of a ‘stylistic reboot', a wise and much-needed move that would help bridge the gap between the family-friendly nature of the first two installments, and the increasingly darker themes of the subsequent films. It's now also considered the best entry by many fans. Things were shifted around a bit too – literally – from Hagrid's Hut to the Whomping Willow, to give Hogwarts and its grounds a more epic feel that would serve the rest of the series well. But the most memorable thing about the third film – or book - is the Time-Turner (although many would argue that it's the awkwardly delivered line "He was their friend!")
In Prisoner of Azkaban, it's revealed that Professor McGonagall has equipped Hermione with a time-traveling device that enables her to attend more classes. However, the ‘Time-Turner' later comes in even more useful when Dumbledore instructs Harry and Hermione to go back and save Sirius Black from having his soul sucked out by the Dementors. To do this, they must rescue a Hippogriff from being beheaded, as they can only rescue Black by air (Buckbeak also doesn't deserve to die, so they're killing two hippogriffs with one stone, or rather not killing). The Time-Turner allows Harry and Hermione to save the day, which makes for some fun sequences in the film's third act (and earlier scenes upon reflection).
However, while magical and innovative, and no matter how seemingly ingenious, time-traveling devices – whether they're actual devices or plot devices – can leave gaping plot holes, just like in any other film. So, in a way, it made more sense than not for J.K. Rowling to keep the Time-Turner shelved for the remainder of the Harry Potter series. That's not to say the Time-Turner hasn't re-emerged since – it's actually the main MacGuffin in West End production Harry Potter and the Cursed Child, in which Harry's son Albus, and Draco's son Scorpius, use the device to go back in time and save Cedric Diggory.
But what happened to the Time-Turner in the main Harry Potter series? There are many questions the Harry Potter series has left us with. Is Harry Potter the Master of Death? Is Dumbledore really dead? But the Time-Turner one is a pretty big question, considering it would have served Harry well in defeating Voldemort. Sure, he ended up destroying the dark lord in the end anyway, but the Time-Turner might have made things easier along the way. On the other hand, it could have also really complicated things and would have also rendered the rest of the series too time-travel-focused. Not only that, but Voldemort could have gotten his hands on it. This alone might explain why the device was, more or less, swiftly done away with after Prisoner of Azkaban.
But where did it actually go once Harry and Hermione no longer needed it? Luckily, there are some solid answers within the Harry Potter canon.
In the Order of the Phoenix book, all Time-Turners at the Ministry of Magic are destroyed during the Battle of the Department of Mysteries and are not replaced. Interestingly, though, they weren't actually destroyed – they fall over when their counter capsizes during the battle, and are thus trapped in an eternal loop of falling over, un-falling over, and then falling over again, rendering them impossible for further use. However, this isn't confirmed until the novel Harry Potter and the Half-Blood Prince. As for Hermione's Time-Turner, at the end of the novel for Prisoner of Azkaban, we learn that Hermione returns hers to Professor McGonagall, which we can assume happens off-screen in the film too. There may be other Time-Turners in use in the Wizarding World, though, but this is not known.
So what about the Time-Turner that's used in Cursed Child? Well, it's a different kind of Time-Turner, allowing its user to travel further back than just five hours (which is the law for students applying for one of the devices to deal with overwhelming studies). The play is set 19 years after we last see Harry and friends at Hogwarts in Harry Potter and the Deathly Hallows Part 2, and as Cursed Child is canon, we now know that Time-Turners still indeed exist, though bound by new laws. In the play, an illegal Time-Turner is acquired by the Ministry Of Magic, only to be later stolen by Albus and Scorpius, who wish to travel back in time to save Cedric Diggory. That Time-Turner ends up being a cheap version and is destroyed, but it is later revealed that Draco Malfoy is in possession of a real one.
So the Time-Turner still very much exists within the Harry Potter universe. And even if they were all destroyed, it's obvious that wizards and witches could conjure up new ones – provided they're smart and powerful enough to do such a thing – whether it's legal or not. Understandably, Time-Turners carry with them strict rules within the Wizarding World and are issued very carefully, so it also makes sense within the Harry Potter universe that these devices aren't made available to everyone.
With all that said, Prisoner of Azkaban and Cursed Child might not be the only Harry Potter stories that have included the use of a Time-Turner. While it's likely to be a major timeline inconsistency, Fantastic Beasts: The Crimes of Grindelwald shows us a younger Professor McGonagall at Hogwarts School of Witchcraft and Wizardry, despite the film being set in 1927, 29 years before she even started teaching there. In fact, it's eight years before she was even born! This has led many fans to speculate that McGonagall is actually in possession of a Time-Turner. Either way, we'll have to wait until the next installment to find out - Fantastic Beasts 3 is due for release on July 15, 2022.
Meanwhile, an HBO Max Harry Potter TV series is also in the works, but if you'd rather jump back in time rather than forward, the open-world game Hogwarts Legacy is also due for release this year, which is set in Hogwarts during the late 1800s.