More than two decades ago, fans built the Harry Potter timeline. Now, J.K. Rowling is slowly breaking it.

Fans love chronologies; a fictional universe with a populated and structured history draws people in by making the world more real. It’s why J.K. Rowling’s own massive universe, Harry Potter and the Wizarding World — which blossomed into existence in 1997 with the release of the first book in the generation-defining series: Harry Potter and the Philosopher’s Stone (or, as Americans know it, Harry Potter and the Sorcerer’s Stone) — continues to resonate with fans decades after its inception. Comprised of books, films, games, theme parks, and Rowling’s fansite, Pottermore, the ever-expanding Wizarding World is, perhaps, one of the most extensive and realistic universes of our generation — despite its deeply decentralized lore and chronology.

Thankfully, for Rowling and the Muggles of the world, Harry Potter fans have taken it upon themselves to organize the Wizarding World’s intersecting stories and timelines by piecing together every known reference, date, and event scattered throughout the sprawling universe, blessing us with a comprehensive timeline not unlike J.R.R. Tolkien’s. They understand that an expansive backstory with specific dates is essential, powerful even. It’s what makes Middle Earth so tangible. But now, Rowling, who’s created a comparably rich and extensive world, seems to be deviating from this meticulous, time-tested practice. Whether intentionally or not, Fantastic Beasts is threatening to severely bend, or entirely break, the Harry Potter timeline fans have spent years crafting.

How Fans Built the Harry Potter Timeline

When Harry Potter and the Philosopher’s Stone was first released, there were zero — yes, zero — hard dates in the text that told the reader when the story was taking place. We only knew one thing for certain: The book started in the summer and lasted for roughly the length of a school year. This format made sense; in the United Kingdom, the school year begins in September and ends in July. All of the subsequent Harry Potter books would be set during a similar time span.

What’s even more amazing is that the entire timeline of the Harry Potter series, and by extension the Wizarding World, hinges on a single piece of information; one solid date given early on in the series. During the events of the series’ second book, Harry Potter and the Chambers of Secrets, Nearly Headless Nick — the Gryffindor house ghost — plans to celebrate his 500th deathday, which occurred on October 31, 1492.

With this one date, fans identified that the events in Chamber of Secrets took place during the 1992-1993 school year. As a result, events from the first two books were easily dated and the timeline began to take its first shape. If Chamber of Secrets began in 1992, then logically the events of Philosopher’s Stone began in 1991 and ran through the following year. More elements fell into place as fans dug deeper.

Philosopher’s Stone included Harry’s 11th birthday, which fans translated to a birth year of 1980. References in the text mention that Harry had been living with the Dursleys for about 10 years when the book began in 1991, meaning that Lily and James Potter would have been murdered by Lord Voldemort in 1981. Fans applied this forensic chronology to everything, and dates were firmly established for events such as Voldemort’s rise and the First Wizarding War (1970-1981), which ended when Harry miraculously survived Voldemort’s Killing Curse.

With the first two books in the series dated, it was easy to fill in everything that came during the following five entries. Each story could be fitted into its place within the fan-built timeline. Mentions of holidays like Halloween, Christmas, and Valentine’s Day helped immensely and, piece by piece, the timeline evolved, expanded, and solidified. While the later books were somewhat vague on hard dates, the release of Harry Potter and the Deathly Hallows clarified and confirmed that the Potters did indeed die in 1981 (their death years were listed when Harry visited his parents’ graves in Godric’s Hollow).

J.K. Rowling herself has tapped into the fan-created timeline in her expansion of the created universe. For example, on September 1, 2017, Rowling tweeted that Albus Potter was due to take the Hogwarts Express to Hogwarts for the first time — a reference to the series’ famous epilogue.

Repairing the First Cracks in the Timeline

No matter how tightly plotted a universe is, chronological errors creep through, and Harry Potter is no exception. The book series alone is riddled with small errors fans have painstakingly documented — like how days of the week often don’t match up with the correct calendar date. Rowling has said on record that math isn’t her strongpoint, and it sometimes shows. To be fair, she probably never dreamed that her works would be analyzed so thoroughly by fans that they would compare the dates in the book to an actual calendar! However, some of the errors are more pronounced and have caused fans to rationalize the errors with creative explanations.

One pesky passage suggests that Hagrid’s position as groundskeeper began shortly after his expulsion from Hogwarts. Hagrid was a contemporary of Lord Voldemort (back when he was known as Tom Riddle), but Molly Weasley, who is younger than both, remembers another groundskeeper called Ogg during her time at the school. Fans speculate that Hagrid might have served as Ogg’s assistant for a while first, though there’s no canon proof.

Another glitch occurs when Rowling states in Goblet of Fire that Severus Snape and Bellatrix Lestrange attended Hogwarts at the same time. According to the fan-made timeline, they would have missed one another by a year or two — in fact, Snape would not have even been a first year until after Bellatrix graduated! Fans swooped in, speculating that Bellatrix had to repeat a number of years after failing her exams — even though that is not something that happens in British schools (though Hogwarts, admittedly, is far from being under the control of the UK’s Department of Education).

A more humorous example involves the mention of a Sony PlayStation in Harry Potter and the Goblet of Fire, during a scene set in 1994. The PlayStation did debut in 1994, but you could only buy it in Japan. A console for the UK market would not appear until the following year. Fans once more came up with a creative explanation: Since Mr Dursley is rich and Dudley is an entitled and spoiled brat, it is not beyond the realm of possibility that Vernon managed to acquire one and import it for his son. Honestly, it tracks.

Harry Potter and the Chamber of Film Paradoxes

The release of the original eight Harry Potter films confused the entire timeline, and for a while, it appeared that the films were not taking place in the same fictional time frame — and fans figured that might make sense. As an adaptation of the original novels, the movies didn’t need to adhere to the book’s timeline. Evidence mounted that the films were shifted forward by several years as anachronisms started to appear, mostly in relation to the Muggle world.

Several scenes supposedly set in the 1990s featured car models that were not manufactured until after 2000. Many scenes set in London during Harry Potter and the Half-Blood Prince and Harry Potter and the Deathly Hallows: Part 1 included buildings that were not constructed until after the 1990s, such as the London Eye (2000), The Gherkin (2004), and Millennium Bridge (2000). In 2010, Deathly Hallows: Part 1 used the song “O Children” by Nick Cave and the Bad Seeds, which wasn’t released until 2004.

Despite these anachronisms, Deathly Hallows: Part 1 confirmed that the films were set in the same timeline as the books. During Harry’s visit to his parents’ graves in Godric’s Hollow, the gravestones showed that Lily and James Potter died in 1981 — the same date given in the Deathly Hallows novel. Fans knew the events of the Wizarding World matched the books’ timeline, even if the events in the Muggle world didn’t. Maybe in that alternate Muggle timeline, PlayStations came out a year earlier. But, as always, it’s a fan-fueled theory meant to rationalize inconsistencies within the story. Or, more simply, a Wizard did it.

McGonagall’s Miraculous Twist

With the release of the Fantastic Beasts movies, fans have had to do a whole lot more sleuthing to keep the timeline alive and accurate. Initially, Rowling’s new series adhered closely to the series’ established dates. For instance, Newt Scamander’s in-universe book, Fantastic Beasts and Where to Find Them, was published in 1927. The 2016 film Fantastic Beasts and Where to Find Them is set in 1926, a year before the book’s release. The second and most recent film in the series, 2018’s Fantastic Beasts: Crimes of Grindelwald, takes place in 1927 and makes a point of mentioning the book’s launch. The minimal timeline checks out.

The first Fantastic Beasts film exists separately from the original Harry Potter universe and characters; only Gellert Grindelwald appears in both. Nothing that happens in Fantastic Beasts directly contradicts anything in the Harry Potter universe. Crimes of Grindelwald, however, is a different story.

With the addition of original Harry Potter characters in Crimes of Grindelwald — more specifically, Albus Dumbledore, Nagini, and a mysterious McGonagall — Rowling brings the two eras of her franchise closer together, and by doing so introduces two potentially timeline-breaking elements. The first surrounds that mysterious McGonagall, who just might be everyone’s favorite Head of Gryffindor House, Minerva McGonagall.

Crimes of Grindelwald, which is, again, set in 1927, introduces us to a young McGonagall rushing around Hogwarts during a flashback, herding Newt Scamander and Leta Lestrange as children. The problem? Rowling has given us an in-depth look at McGonagall’s life which indicates that she began teaching at Hogwarts two years after graduating. In Harry Potter and the Order of the Phoenix, we discover that McGonagall has been working at Hogwarts for 39 years, meaning she should’ve graduated in 1954. Since McGonagall was almost 19 years old when she finished Hogwarts, her birth year can be inferred as 1935. After crunching the numbers, it’s pretty impressive — and surprising — to learn that Professor McGonagall was actively teaching at Hogwarts years before her supposed birth.

There could, of course, be a magical explanation, such as a Time-Turner — but why? Admittedly, McGonagall’s birth year was never set in stone, but it’s based on several very concrete clues from Rowling herself. If that is Minerva McGonagall in Crimes of Grindelwald, it would be a huge twist for fans that would age her considerably.

Here, Rowling might be retroactively establishing that McGonagall is a lot older than we previously thought. Or maybe this McGonagall is a relative of the Professor McGonagall that fans were first introduced to in Philosopher’s Stone. Retroactive continuity is nothing new in fandom and this appears to be the first major one that Rowling is introducing to her universe. Or, conversely, it could be an error or oversight.

Even if [Professor McGonagall] being in Fantastic Beasts [Crimes of Grindelwald] is just a mathematical error, it doesn’t excuse it. In fact, it kind of makes it worse because it shows [Rowling] didn’t even bother to fact check anything. Why write dozens upon dozens of short stories and notes if you’re not even going to bother to make sure they align up? – Darkanine, Harry Potter Community member

The Credence Conundrum

The second timeline-bending twist in Crimes of Grindelwald is, obviously, the reveal that Credence Barebone is actually Aurelius Dumbledore, Albus’ brother. And, honestly, this math simply doesn’t work out at all. Albus had two known siblings: His brother Aberforth (who outlived him), and his sister Ariana (who was killed in 1899). Dumbledore’s mother, Kendra, died shortly before Ariana, and his father, Percival, was locked up in Azkaban in 1890 and died in prison. Based on the text in the Crimes of Grindelwald script book, Credence was definitely a baby in 1901 during the Atlantic boat crossing flashback. Credence clearly cannot have been born to Albus Dumbledore’s parents if one was already dead and the other was enjoying the comforts of Azkaban.

Of course, it’s possible that Grindelwald is lying about Credence’s identity. At this stage, it’s too early to call this a break in the known timeline or canon, simply because there are three more films in the Fantastic Beasts series to come. We know — or hope, at least — that the entire situation will be explained at some point.

But that has not stopped rampant speculation. One of the more popular theories (aside from Grindelwald being a lying liar) is that the Obscurus inside Credence is not of his own making, but is somehow a remnant of Ariana Dumbledore. Ariana, Albus’ sister, was killed during a duel between Albus, his brother Aberforth, and Grindelwald in 1899. It’s never stated, but she might have been an Obscurial, just like Credence. It’s currently the only possible connection between the two. Of course, this doesn’t explain why Grindelwald calls Credence “Aurelius,” which makes alliterative sense, but absolutely no chronological or narrative sense.

“I think Rowling has every right to adjust the canon of her own creation as much as she wants. It belongs to her, to do with as she wishes. I’m glad [she] is still interested in developing and expanding her world, and I’m grateful that she continues to share these things with us. I’m loving the Fantastic Beasts series and I look forward to each movie. I even hope there’ll be more after it is concluded – canon be damned.” – CaptainKaibyo, Harry Potter Community member

How Fans Feel About Breaking the Timeline

At what point should an established canon take precedence over advancing the story? Large fictional universes often run into this problem. When planning began for the new Star Wars cinematic trilogy in 2014, the decision was made to de-canonize over 30 years’ worth of the books, comics, and video games that comprised the Expanded Universe. The decision gave creators room to create new cinematic storylines without needing to worry about continuity.

Films like Superman Returns ignored Superman III and IV in favor of continuing the story right from the end of Superman II. More recently, 2018’s Halloween ignored the whole string of sequels that crowded the canon since the original movie’s 1978 release, and began the action right after the first film’s events. The two movies even share identical titles. It’s not unheard of for the creators behind long-running franchises to reinvent whole worlds in order to revive and refresh the timeline when it’s in greater service of the story. However, these timeline issues likely won’t just go away if Rowling’s plan is to continue bringing the Fantastic Beasts and Harry Potter timelines closer together.

So does it matter if Rowling breaks the canon of her own creation? Is canon so inviolate that it cannot be sacrificed for the greater good of the story? When asked for their thoughts on the matter, the Harry Potter Community — an entirely fan-run community comprised of nearly 10,000 members, with a little over a quarter million page views in 2018 alone — had mixed reactions. Theories about Credence’s identity and Professor McGonagall’s presence are already buzzing, and fans are split on their views regarding breaks in the timeline, with 25% finding her canon-breaking ways inexcusable and 27% being unfazed by the inconsistencies plaguing the Potterverse.

But there’s another group of fans worth mentioning, the 48% who believe Rowling will provide a plausible explanation before the Fantastic Beasts films wrap up. In fact, many went out of their way to patch up the timeline for her, some even pointing to popular theories from the SuperCarlinBrothers. Their commitment and dedication makes one thing clear: the community needs this timeline to work, perhaps even more so than Rowling herself. But instead of grabbing their pitchforks and torches and setting the whole thing ablaze, Harry Potter fans have put their faith in the storyteller. And if the clarity they crave never comes, they’re more than willing to step up and fix the timeline themselves for the sake of the Wizarding World.

With three Fantastic Beasts movies to go, only time will tell how much work fans will have to put into amending and justifying twists and bends in the timeline they’ve spent two decades building.