The Day of the Doctor (TV story)

 was the fiftieth anniversary special of Doctor Who. The episode featured the return of David Tennant as the Tenth Doctor and the appearance of John Hurt as a previously unknown incarnation of the Doctor: the War Doctor. Furthermore, the War Doctor's regeneration was shown, into what appeared to be the Ninth Doctor, completing a missing link in the chain of incarnations. The special also included the surprise debut of Peter Capaldi as the Twelfth Doctor, as well as a cameo from an elderly Tom Baker, the former Fourth Doctor, whose role was kept ambiguous as either the Doctor or someone else entirely — the Curator. The episode provided a chance to reveal a missing element of the Last Great Time War that dramatically altered the outcome as viewers were previously led to believe. Instead of allowing Gallifrey to be destroyed, the Doctors were able to save it, giving the current incarnation a chance to forever shed his guilt from the outcome and begin a new mission to find his way home.

The episode was certified by the Guinness Book of World Records as the largest ever simulcast of a television drama, airing in 94 countries and 1,500 theatres worldwide.

The episode was shot, broadcast and screened in cinemas in stereoscopic 3D. Despite confessing that he was not a big fan of 3D movies, writer and show runner Steven Moffat came up with the idea of shooting the episode in 3D and despite his initial worries, found the 3D version to be "better" and "more satisfying" than the 2D version. Knowing that the vast majority of viewers would have watched it in 2D, director Nick Hurran made sure that his shooting style wasn't influenced "too much" by the episode's use of 3D. Nonetheless, Hurran meticulously researched into which 3D films worked and didn't and how before shooting; Steven Moffat believing that Hurran watched "every 3D film ever made". (DWM 468)

Synopsis
The Doctors embark on their greatest adventure in this 50th anniversary special. In the 21st century, something terrible is awakening in London's National Gallery; in 1562, a murderous plot is afoot in Elizabethan England; and somewhere in space an ancient battle reaches its devastating conclusion. All of reality is at stake as the Doctor's own dangerous past comes back to haunt him.

Plot
A police constable walks the beat by the Coal Hill School and passes by a sign advertising "I.M. Foreman, Scrap Merchant". Inside the school, Clara Oswald is giving a lesson. As her students leave, a teacher runs into the classroom informing Clara that her "doctor" called, and left an address. She grabs her helmet and hops on her motorbike. Finally spotting the TARDIS, she drives straight into its open doors. The Doctor, perusing a copy of Advanced Quantum Mechanics, welcomes Clara back with a huge hug. Unexpectedly, the TARDIS takes off without starting the engines.

Startled, the Doctor looks out to see a helicopter carrying the TARDIS away from the field; it's UNIT. He calls their head of Scientific Research, Kate Lethbridge-Stewart, and learns that he has been summoned to the Tower of London. Kate is surprised to learn that he is on-board the TARDIS, which they thought was empty and were moving for convenience. She has it and him brought directly to the "scene of the crime". Upon arrival, he is handed sealed orders from Queen Elizabeth I and taken into the National Gallery for proof of her credentials.

As they walk, the Doctor explains his relationship with UNIT to Clara, who is skeptical of the Doctor having an actual job. They stop in front of an impossible painting, something that belongs neither on Earth nor in 2013: an oil painting in 3-D. It depicts the fall of the Gallifreyan city of Arcadia on the last day of the Time War. Kate tells the Doctor that there is some controversy over the work's name. It is either named "No More" or "Gallifrey Falls". The painting is a slice of frozen time, a form of Time Lord art.

The Doctor is visibly disturbed by the painting. As his old memories awaken, he shares with Clara his darkest secret: the life he has tried to bury for years. There was a past incarnation of the Doctor that fought in the Time War, and made the ultimate decision to eliminate the Daleks and the Time Lords. And it was done on the very day this painting depicts...

As the Daleks ravage Arcadia, the Gallifreyans are running in fear. There is little hope of survival. As children cry and the people scream, a soldier messages the High Council of Time Lords: Arcadia has fallen. He looks around and sees the Doctor's TARDIS. Then the elderly voice of the "War Doctor" asks him for his gun. He carves a message for both warring civilizations to see into a nearby wall: NO MORE. As Daleks attempt to exterminate innocent Gallifreyan refugees, the Doctor's presence draws their attention away from the innocent people and leads them to the wall with the message. He launches his TARDIS through the wall, demolishing several Daleks. The Doctor's escape from Arcadia is witnessed by one surviving Dalek of the attack, though it is bisected. It questions the meaning of "NO MORE", bellowing "Explain! Explain!" The nearby Gallifreyan soldier shoots the Dalek with his gun, killing it and then causing it to explode.

The High Commanders gather in the War Room, planning their next moves, with the General dismissing the High Council's upcoming plans as "they have already failed". They receive the Doctor's message, and the General is not pleased to learn of his presence, calling him a madman. A Time Lady rushes in to inform the War Council that there has been a breach in the Omega Arsenal in the Time Vaults. The most feared and forbidden weapon in the universe is missing: The Moment. The Doctor has stolen it, and intends to use it to end the Time War once and for all. The Time Lords have already used all of the previously forbidden weapons, but dared not unleash this weapon in particular. It was said that the Moment was so advanced as to have developed a conscience, and could stand in judgement of the user. The General muses that only the Doctor would be mad enough to use such a weapon.

The Doctor strides across a desolate desert, a burlap sack over his shoulder. He eventually enters a barn-like dwelling, where he uncovers a complicated mechanical box, covered in gears. While he puzzles over how to activate it - grumbling "Why is there never a big red button?" - he hears a rustling sound. He opens the door and calls out. A girl's voice behind him reassures him that it’s "just a Wolf". Startled, he turns around to see what appears to be Rose Tyler. He doesn't recognize her, as this point in his timeline predates his first meeting with Rose. He grabs her arm and throws her out the door, only for her to appear again, sitting on the Moment. She begins questioning the Doctor as to his motives and rationalizations (though it looks like she is making fun of him). Not realizing what she is, he orders her out, and then burns his hand on the box. Impishly, she guides the Doctor to realize that she is the interface of the Moment. She can hear the Doctor's thoughts, and has attempted to assume the form of a familiar figure from his past; however, the Moment has a history of confusing the past with the future, and so has chosen the form of Rose Tyler as the Bad Wolf to be its manifestation. War-weary and bitter, the elderly Time Lord tells her to stop calling him "the Doctor"; he claims he has lost the right to bear the title. She replies that he will be the one to save the universe. He explains that the suffering of the universe is too great, and he must end it. Like a conscience, she challenges his words and actions, guiding him towards his future. He will destroy the Daleks, but he will also murder his own people, asking him how many children on Gallifrey will die, but he has no idea. After suggesting that one day, he will find a way to count them, the Moment opens a window in time, to show him the man he will become. A time fissure opens - and a fez falls out, much to the mutual confusion of the Doctor and the Moment.

Back in the 21st century, Kate explains that Queen Elizabeth left the painting to prove that the orders do come from her. The Doctor breaks the seal and reads her words: "My dearest love: I hope the painting known as Gallifrey Falls will serve as proof that it is your Elizabeth that writes to you now. You will recall that you pledged yourself to the safety of my kingdom. In that capacity, I have appointed you Curator of the Under-Gallery, where deadly danger to England is locked away. Should any disturbance occur within its walls, it is my wish that you should be summoned. Godspeed, gentle husband."

As Kate leads the Doctor and Clara away, a nearby UNIT scientist named McGillop receives a mysterious phone call. Befuddled, he stares at the painting, wondering why he should move it.

In England in 1562, the Tenth Doctor and Queen Elizabeth I ride out of the TARDIS on horseback, the Doctor having proven that it really is bigger on the inside. They share a picnic on a hill, after which he proposes marriage. When she joyfully accepts, the Doctor accuses her of being a Zygon shapeshifter that has replaced the real Elizabeth. He whips out a "device that goes ding" to prove that she is a shapeshifter, before realizing that it was the horse they were riding. They run for their lives, the Doctor now an engaged man. They split up in the woods, but Elizabeth is accosted by the Zygon. The Doctor runs through the woods, even threatening a rabbit before he is reunited with Elizabeth. However, a doppelganger of her appears, and he is unable to tell who is who. Suddenly another time fissure appears, and a fez falls through, shocking the Doctor and company.

In 2013, Kate welcomes the Eleventh Doctor and Clara to the Under-Gallery, established by Elizabeth I to house dangerous art. The Doctor notices that the floor is covered in stone dust, and asks a scientist named Osgood to analyze it (with a triplicate report and lots of graphs). As they walk through the gallery, the Doctor spots a fez in a glass case and immediately dons it, much to the bemusement of Clara, who wonders if he can ever go past one without putting it on (answer: no).

Kate shows them more 3-D paintings, all landscapes, with the broken glass from their shattered frames covering the floor. The Doctor notes that the glass has been shattered from the inside, and Kate says that they all contained figures, which are now missing. Suddenly, another time fissure opens. Annoyed, the Doctor faintly recalls seeing the fissure before, before realizing that the fez that had fallen through in 1562 was the fez he was now wearing. Delighted, he throws the fez into the fissure and follows it. Clara tries to follow, but Kate restrains her.

The Eleventh Doctor falls through the fissure and lands in front of the Tenth in the sixteenth century. Stunned, the Tenth Doctor dons the fez himself. The Eleventh pops up and gabbles excitedly about how skinny his predecessor is, which makes the Tenth realize who he is. They incredulously pull out their sonic screwdrivers and compare them. As they begin bickering, the time fissure increases in intensity. The Doctor orders the two Queens to run away. They both kiss the Tenth Doctor and flee. After pointing out that one of the women his counterpart just kissed was definitely a Zygon, the Eleventh shouts through the funnel to Clara. Hypothesizing that the fissure can go both ways, he tosses his fez in, but it fails to appear in Clara's time. Kate then leaves, to call one of the UNIT members to bring her the Cromer file, not noticing a dark shadow behind her.

At the end of the Time War, the War Doctor picks up the fez and steps into the fissure. Back in 1562, the two Doctors try to reverse the polarity, but the use of two sonic screwdrivers at once confuses the polarity, resulting in the War Doctor falling through, landing in front of his future selves. He jovially greets them, asking after the Doctor and mistaking them for his companions. The two older Doctors simply pull out their sonic screwdrivers, affirming their identity to their younger self. Completely unimpressed by his future incarnations, the War Doctor asks if he is going through a mid-life crisis.

Suddenly, they are surrounded by the Queen's soldiers. They are threatened by them, but Clara's voice sounds from the fissure, allowing the Doctors to convince them that she is "The Wicked Witch of the Well". Kate has, at that point, returned to Clara. The Queen returns to the group, implying that her human counterpart is dead. She has the trio of Doctors arrested and taken to the Tower of London (with the Eleventh loudly hinting for her to take them there). The hint is picked up on by Kate, who takes Clara to the Black Archive to retrieve Jack Harkness' vortex manipulator.

The Doctors are thrown in a cell with a wooden door. The War Doctor tries to sonic the door, but it fails. The Tenth asks why these three Doctors have been brought together.

In the present, Osgood and McGilop are reading the results of the analysis of the stone dust. The dust is from materials not found in the structure of the building, but common in statues. Osgood realises that the statues must have been smashed, and suddenly understands why: the inhabitants of the paintings needed a hiding place. The Zygons reveal themselves from underneath the dust cloths covering what the humans had believed were statues. The aliens accost McGilop, and corner Osgood. Osgood prays for the Doctor to save her, but instead of being killed, she is faced with her duplicate. The Zygon taunts Osgood, but she gains the upper hand by tripping the alien with her scarf, and runs.

Kate and Clara enter the Black Archive, housing the most dangerous alien tech recovered by UNIT. Its contents are so top secret that its staff has their memories modified every day. Apparently, this has happened to Clara at least once, as she has already obtained the necessary clearance to enter the archive. They view the Vortex Manipulator, by trying to find the activation code. The Doctor has the code, but he hasn't informed UNIT of it. A scientist phones Kate, and she orders him to send a picture of some numerals (possibly the code) that the Eleventh Doctor carved into the wall of the cell in 1562 for them to find centuries later. Osgood and McGilop enter the Archive, to Clara's surprise. They and Kate reveal themselves as Zygons. As they prepare to replace Clara, she sees the picture of the numerals on the phone. Taking a desperate gamble, she enters the code and travels to the past.

In the Tower of London, The Eleventh Doctor scratches the activation code onto a wall in their cell, while the other two Doctors puzzle out how to escape. The War Doctor proposes an isolated sonic shift in the door molecules in order to disintegrate the door, but the Tenth Doctor rejects the idea, saying it would take centuries to calculate the necessary formula. The War Doctor starts bickering with the Tenth and Eleventh Doctors, chastising them for their shame of being "grown-up". Subdued, they look at him darkly, reminding him of the day he ended the Time War (unaware that this Doctor is actively in the process of making that choice). The Moment reappears, unseen and unheard by the other Doctors, and urges the War Doctor to ask his future selves the question that he needs to know: How many children died on Gallifrey that day. The Eleventh Doctor claims he doesn't know, and that he's forgotten the events of that day; he's so old that he's not even sure of his age anymore, so old that he can't remember if he's lying about his age. However, the Tenth Doctor angrily asks how the Eleventh could ever forget something as important as this particular number, and bitterly states that there were 2.47 billion children on the planet that day. The Moment explains that the Tenth Doctor has become "the man who regrets" and the Eleventh "the man who forgets". They are the future of the Doctor.

The Moment reminds the War Doctor that his sonic screwdriver, at the most basic level, is the exact same device as the ones used by his counterparts; "Same software - different face". He realizes that if he scans the door and implants the calculations as a permanent subroutine in the screwdriver, it will take hundreds of years to work out the formula necessary to disintegrate the door, meaning that the Eleventh Doctor's screwdriver, being essentially the same as the ones before it, has the completed calculation ready. They exuberantly congratulate themselves on their cleverness, before Clara pushes open the door, which has been unlocked the entire time. Clara chastises the three Doctors for being so obtuse, and the Queen comes in, telling them that she left the door unlocked the entire time as a test. She takes them down to the Zygons' lair to show them their plan.

Osgood walks in the halls of the Under-Gallery, before discovering the real Kate trapped in a Zygon nest. She frees her, but Kate bemoans the fact that the Zygons now have control of the Black Archive.

The Doctors and Clara follow the Queen to the lair, whereupon they discover that the Zygon homeworld was destroyed in the early days of the Time War, and so they have decided to take Earth as their new home. However, the sixteenth century version of Earth is too primitive to be comfortable to the invading shapeshfiters, so they intend to invade the cushier future in order to establish their new homeworld. They therefore have translated themselves into stasis cubes, which are the Time Lords' three-dimensional paintings. The Tenth Doctor berates the Zygon commander for doing a lousy job of replicating the real Queen Elizabeth, but she reveals (to his mortification) that she is the real Elizabeth: She slew her twin in the forest and took her place as Zygon commander. She calls on the Doctor to save England, but first whisks him away to be married (with his past and future selves as reluctant witnesses, and an enthusiastic Clara).

The three Doctors and Clara return to the Tenth's TARDIS (with the other two insulting the current desktop theme). The presence of three different Doctors causes the TARDIS to short a bit, showing the interior of the War Doctor's TARDIS, then finally the most current TARDIS desktop (which also receives an insult). They set sail for the Black Archive.

Kate, Osgood, and McGillop confront their doppelgangers in the Black Archive. Kate threatens to detonate a nuclear warhead beneath the Tower, destroying all of London in order to protect the planet from the Zygons, and voice-activates it, blocking her Zygon duplicate's attempts to stop the countdown with her identical voice pattern. The Eleventh Doctor's voice crackles on via the space-time telegraph he had once given to her father, begging Kate not to detonate but she cuts him off. He tries to land, but the Tower of London is TARDIS-proof. However, the War Doctor figures out a way to get in - the stasis cubes. The Doctor calls McGillop in the past, and instructs him to bring the "No More"/"Gallifrey Falls" painting to the Black Archive.

The two Kates fight over the detonation, both needing to agree in order to stop the detonation. The real Osgood begs the Doctor to save them again, as the Doctors and Clara force their way out of the painting, having frozen themselves in it earlier. The three Doctors hand the Kates an ultimatum: They trigger the memory modifiers to confuse everybody as to whether they are a Human or a Zygon. Then, if they stop the detonation and create a peace treaty (which is sure to be incredibly fair, as the negotiators can't remember which side they're on), they will have their memories restored. Utterly confused over their identities, the two Kates stop the detonation in the nick of time and begin to negotiate the treaty.

As they hash it out, Clara speaks to the War Doctor. She has somehow figured out that he hasn't used the Moment yet, explaining that her Doctor always talked about the day he wiped out the Time Lords. She says that he would do anything to take it back, but the War Doctor remains convinced that his actions will save billions of lives in the future. Across the room, the War Doctor sees the form of the Bad Wolf once more. The Moment has come. He tells the interface he's ready, and Clara turns to find who he's talking to; when she turns back, he's vanished.

Returned to the barn, the War Doctor stands in front of the Moment, which has simplified its interface by his request; the trigger mechanism is now a big red button for him to push. The interface questions him once more, trying to convince him of his goodness. He still doesn't believe he is worthy of the name "Doctor", losing all hope for himself and his people. The interface reminds him of his hope as his future selves step out of their TARDISes. They join him at the Moment, finally forgiving him, and themselves, for his actions, ready to support the man who was the Doctor more than anybody else. The three of them prepare to push the button together, but Clara tearfully objects. She knew that "the Doctor" had activated the Moment and destroyed his homeworld, but she had never imagined the Eleventh Doctor, her Doctor, with his hand on the button.

The reality of the Time War projects around them: children crying, innocents suffering. The Doctor could not find another way to end it all, but Clara believes in a different solution. She reminds the Time Lord of who he is: the Warrior, the Hero, and the Doctor. They've had plenty of warriors, and what he will do is a heroic act unto itself. What the universe needs now is a Doctor who lives up to the name he chose for himself: never cruel or cowardly, never giving up, never giving in. A new day dawns on Gallifrey: a day of hope.

At that, a brilliant new idea descends on the room; the Eleventh Doctor says that he's had a long time to think about it - he's changed his mind! The intent of the Moment worked: The War Doctor saw the future he needed to see. Picking up on his future self's idea without explanation, the War Doctor exclaims that he could kiss "Bad Wolf girl", which catches the Tenth's attention, only for him to be distracted from it as he realizes what his counterparts were getting at and agrees that it's a wonderful idea. They change their minds about using the Moment, and the Eleventh Doctor disarms the device with his sonic screwdriver. Instead, they intend to freeze Gallifrey in a moment in time, slipped away in a pocket universe, the way the Zygons froze themselves into Time Lord art. When Gallifrey vanishes, the sphere of Dalek ships surrounding the planet and firing constantly will be exterminated in their own crossfire, and the universe will believe that the two races destroyed each other.

On the last day of the Time War, another message from the Doctor appears before the High Command: GALLIFREY STANDS. The three Doctors race in their TARDISes towards Gallifrey, and transmit to the War Room. Three transmissions, each showing a different Doctor (much to the General's dismay), appear. They explain their mad plan to save Gallifrey. They position themselves around the planet equidistantly, and prepare to freeze it through the stasis cubes. The General objects, claiming that the calculations would take centuries, but the Eleventh Doctor is well prepared for the task. After all, he's had centuries to think about it.

At that, the voice of the First Doctor is heard contacting the War Council. Ten more phone boxes fly around the planet, and all the past incarnations of the Doctor come together to save Gallifrey – even a thirteenth incarnation from the Doctor's days yet to come. As the Daleks increase their attack upon seeing the thirteen TARDISes, the General tells the Doctor to do it now. After a flash and a colossal explosion, the space becomes empty and quiet.

Back in the National Gallery, the Tenth, Eleventh, and War Doctors muse on the ambiguity of whether their plan succeeded. The presence of the mysterious painting of the fall of Arcadia remains an enigma to the three Doctors. The War Doctor bids a fond farewell to his replacements, who finally address him as "Doctor": a man fully worthy of the title, even if he only knows it briefly. The War Doctor and the Tenth Doctor won't be able to retain their memories of these events. They will forget them completely until they catch up to their Eleventh incarnation, as the time lines are out of sync. However, before the memories can fade fully, as the War Doctor pilots his TARDIS away, he notices that his body has worn thin again. As he is dying of old age, regeneration energy begins to overtake the War Doctor. With no regrets and a heart full of hope, he only hopes the change will leave him with less conspicuous ears this time. He smiles peacefully as his next regeneration begins.

Acknowledging that he won't be able to remember the answer, the Tenth Doctor questions his successor as to "where they're going" that the Eleventh Doctor clearly wants to forget; he finally relents and reveals that they are destined to die on Trenzalore, in battle, with millions of lives lost. The Tenth Doctor says that's not how it's supposed to be, but the Eleventh Doctor tells him it is determined now. Preparing to leave, the Tenth Doctor tells himself that he's glad his future is in good hands. He kisses Clara's hand, and with a smile, starts to step into his TARDIS. Before he does, he expresses his desire to change their final destination of Trenzalore, saying: "I don't want to go." As the TARDIS dematerialises, the Eleventh Doctor remarks "he always says that."

Clara asks the Doctor if he would like to sit and look at the painting for a little while. He smiles, asking how she knew. Clara kisses him on the cheek and tells him that she always knows - it's his sad old eyes. As she steps into the TARDIS, she mentions that an old man, possibly the Curator, was looking for him.

The Doctor muses out loud that he would be a great curator. He could call himself "the Great Curator", retire and become the curator of this gallery. A very familiar voice affirms that he really might. The astonished Doctor looks over to see a very familiar face standing next to him. An old man who greatly resembles the Fourth Doctor speaks to him of the painting, which he says he acquired under most unusual circumstances. He tells the Doctor that its two names are actually one: the true title of the painting is "Gallifrey Falls No More". The Doctor realises that he was successful, and Gallifrey was indeed saved. The mysterious man reveals that it is simply "lost", and that the Doctor has a lot to do. The Eleventh Doctor concludes that he has a mission, the mission of a lifetime: he must find Gallifrey and return it and all its people to the universe. Later, the Doctor speaks of his dreams, as he is seen to walk through the TARDIS console room. He says that he finally realises where he has been travelling all this time: home. He simply has taken the long way around. As he exits the TARDIS in the dream, the Doctor joins his eleven past selves in gazing up at the magnificent planet in the sky, determined to find Gallifrey and save his home once and for all.

Cast

 * The Doctor - Matt Smith
 * The Doctor - David Tennant
 * The Doctor - Christopher Eccleston
 * The Doctor - John Hurt
 * The Doctor - Paul McGann
 * The Doctor - Sylvester McCoy
 * The Doctor - Colin Baker
 * The Doctor - Peter Davison
 * The Doctor - Tom Baker
 * The Doctor - Jon Pertwee
 * The Doctor - Patrick Troughton
 * The Doctor - William Hartnell


 * Clara - Jenna Coleman
 * Rose - Billie Piper
 * Tom - Tristan Beint
 * Kate Stewart - Jemma Redgrave
 * Osgood - Ingrid Oliver
 * Time Lord soldier - Chris Finch
 * Androgar - Peter de Jersey
 * The General - Ken Bones
 * Arcadia father - Philip Buck
 * Time Lord - Sophie Morgan-Price
 * Elizabeth I - Joanna Page
 * Lord Bentham - Orlando James
 * McGillop - Jonjo O'Neill
 * Atkins - Tom Keller
 * Zygons - Aidan Cook, Paul Kasey
 * Voice of the Daleks & Zygons - Nicholas Briggs
 * Dalek 1 - Barnaby Edwards
 * Dalek 2 - Nicholas Pegg
 * Voice over artist - John Guilor

Uncredited cast

 * The Doctor - Peter Capaldi
 * The Curator - Tom Baker

Locations

 * The Zygon homeworld was destroyed during the first part of the Last Great Time War.

Technology

 * The Eleventh Doctor uses the TARDIS console's friction contrafibulator (TV: Vincent and the Doctor) to stabilise the control room desktop theme. (TV: Time Crash)
 * The number the Eleventh Doctor calls McGillop from is the same as Martha's old mobile - the one left on the TARDIS. This implies that the Doctor adopted this number as his main one.

Individuals

 * Jack Harkness's vortex manipulator was saved in the Black Archive of the UNIT after one of his deaths. It later ended up in the possession of the Eleventh Doctor and Clara Oswald.
 * The board containing photos of Clara's last visit to the Black Archive also showcase photos of previous associates of the Doctor, including Wilfred Mott, Rory Williams, Amy Pond, River Song, Kamelion, Martha Jones, Peri Brown, Alistair Gordon Lethbridge-Stewart, Nyssa, Donna Noble, Captain Yates, Adric, Sara Kingdom, Tegan Jovanka, Barbara Wright, Polly Wright, Grace Holloway, Ben Jackson, Ian Chesterton, Susan, Brigadier Winifred Bambera, UNIT Captain Erisa Magambo, and Rose Tyler.
 * Kate Lethbridge-Stewart's mobile phone has a TARDIS dematerialisation sound set as her ringtone when the Doctor calls.
 * Clara quotes Marcus Aurelius to her class.

The Doctor

 * The Doctor's age is discussed by the three incarnations:
 * While confronting a rabbit which he briefly believes to be a Zygon in disguise, the Tenth Doctor says that he is 904 years old.
 * When asked how old he is by the War Doctor, the Eleventh Doctor says that he doesn't know and has lost track, settling on "Twelve hundred and something, I think, unless I'm lying." He goes on to say that he is so old he couldn't remember if he was lying about his age.
 * The War Doctor in turn says that he's 400 years younger than the Eleventh Doctor at this point, making him approximately 800 years old. This would suggest that his successor may have travelled for about a century before first meeting Rose Tyler, as he tells her he is 900 years old. (TV: Aliens of London)

References to the real world

 * When Elizabeth explains how she killed her Zygon duplicate, she says, "I may have the body of a weak and feeble woman, but at the time, so did the Zygon." This is a direct reference to the, in which she was credited as saying, "I know I have the body of a weak, feeble woman; but I have the heart and stomach of a king, and a king of England too..."
 * The Eleventh Doctor calls the Tenth Doctor "Dick Van Dyke".

Ratings

 * 10.18 million (United Kingdom)
 * 77 million (World)

Specific to theatrical presentation

 * Two specially recorded scenes were shown before the special in its showing in cinemas. The first featured Dan Starkey as Commander Strax, accompanied by his Sontaran clone batch, lecturing the viewers on cinema etiquette. The second featured Matt Smith and David Tennant as the Eleventh and Tenth Doctors instructing viewers to put on their 3D glasses. The second ends with John Hurt's War Doctor suddenly appearing behind the two Doctors who turn towards him while he has his back to them as the feature starts.

Specific to the 3D version

 * The original Doctor Who logo is not only in black and white; a 3D effect is added to suggest the logo moving towards the viewer.
 * The 3D paintings are obviously more 3D in the 3D version.
 * As the Eleventh Doctor walks out of the TARDIS onto the cloud bearing his other selves at the very end of the story, the effect is considerably "more 3D" than viewing the 2D version would suggest.

Common among all versions

 * The story is fronted by the version of the title sequence used on the original episode "An Unearthly Child", modified to include a BBC logo, and slightly shortened. (This version is slightly different than the opening used on the unaired pilot episode.)
 * The opening scenes further mimic the original open to TV: An Unearthly Child: the first shot shows a police officer going by a sign for 76 Totter's Lane, and the second shot is set at Coal Hill School as class dismisses. Clara is now a teacher at Coal Hill School. A sign shows that I. Chesterton is chairman of the school's Board of Governors, also showing that a W. Coburn is headmaster - a likely reference to Anthony Coburn, who wrote An Unearthly Child, and Waris Hussein, Doctor Who's original director.
 * Day is the sixth televised multi-Doctor story. The others are: The Three Doctors, The Five Doctors, The Two Doctors, Time Crash, and The Name of the Doctor.
 * The end credits list all the actors who have played the Doctor in the reverse order of their incarnations (with the exception of Peter Capaldi, who was completely uncredited for his brief appearance). As a result, Matt Smith and David Tennant are listed first and second respectively, but Christopher Eccleston is credited above John Hurt.
 * Actor John Guilor is credited as 'Voice Over Artist' in the credits, although they do not say which role he voiced. Castingcallpro.com credits him as the voice of the First Doctor.
 * Radio Times credits David Tennant as 'The Tenth Doctor', John Hurt as 'The Other Doctor' and Billie Piper as 'Rose Tyler'.
 * Jonjo O'Neill (McGillop) is erroneously credited as 'McGuillop' in Radio Times.
 * This is the first on-screen appearance of the Daleks not to feature those of the New Dalek Paradigm in the Steven Moffat era. This doesn't likely mean that the multi-coloured Daleks are gone, because all Daleks in this story predated the multi-coloured versions introduced in TV:Victory of the Daleks.
 * As Clara leaves the school a clock can be seen to display the time as 17:16, the broadcast time of "An Unearthly Child".
 * The access code for the vortex manipulator is "1716231163". This is a reference to the time (17:16) and date (23.11.63) that the episode TV:  An Unearthly Child first aired.
 * When paired with the prequel episode TV: The Night of the Doctor, the titles of both episodes reflect opposite moments in the Doctor's personal lifetime. Night depicts the Doctor giving in to despair after suffering an absolute failure, whereas in Day, he has an absolute triumph. The two episodes also bookend the War Doctor's lifetime. Night shows his birth, and Day shows his death.
 * The Ninth Doctor's scene in the climax is footage from TV: The Parting of the Ways.
 * This is the final televised story to feature the Eleventh Doctor in a fez.
 * The Fifth Doctor's dialogue, "Soon be there!" is taken from TV: The Five Doctors.

Production errors

 * There is a basic hair continuity error in the scene where Elizabeth and her duplicate catch up with the Tenth and Eleventh Doctors in the forest. As the two Elizabeths each kiss the Tenth Doctor, the Eleventh's quiff inexplicably escapes from underneath the fez — mostly when he is out of focus — and then is magically back under the fez when he's in tighter shots.
 * When the Tenth Doctor has been kissed by Elizabeth in their wedding, his collar is up in one shot, and down in the next.
 * A close-up of the screen of the Space-Time Telegraph shows that it refers to the Brigadier's last name as "Left-Bridge" Stewart.
 * When all thirteen incarnations of the Doctor arrive to hide Gallifrey in a pocket universe, the Seventh Doctor first appears in his yellow pullover with question marks. When he appears again, his costume changes to the one he wore in the TV Movie and he is now in the Victorian parlor console room. When he appears for the third time, he goes back to wearing the pullover he originally wore in the television series. This emphasises that the archive footage used to generate his presence among the other Doctors has been pulled from asynchronous moments of his life, the early and late periods to be exact.
 * At the end of the special, when the three Doctors are in the museum, the Tenth Doctor asks what the painting is actually called. In that shot, the door to his TARDIS is open. In every shot after that, the door is closed.
 * The last scene of the special, where the Eleventh Doctor is walking out of the TARDIS onto the cloud with his other incarnations, the TARDIS door handle has been obviously removed.

Deleted scene

 * A short deleted scene on the BBC Doctor Who website features the War Doctor, the Tenth and Eleventh arriving at the tower of London in ankle shackles. The Eleventh says his shoes "bring the cool" and that the Tenth "wouldn't understand the cool," whilst the exasperated War Doctor declares they haven't drawn breath "since Richmond".

Continuity

 * A police officer walks by a sign for I.M. Foreman's scrapyard at 76 Totter's Lane.
 * Clara is now a teacher at Coal Hill School. A sign shows that I. Chesterton is chairman of the school's Board of Governors.
 * Clara rides a motorbike into the TARDIS console room. A policeman from San Francisco previously rode a motorbike into (and very quickly out of) the TARDIS. (TV: Doctor Who) The Tenth Doctor similarly rode a moped out of the TARDIS (TV: The Idiot's Lantern), and the Eleventh Doctor did the same with a motorbike (TV: The Bells of Saint John).
 * While the TARDIS previously showed dislike for Clara, Clara is now able to close the TARDIS doors with just a snap of her fingers, suggesting it has grown to like her after saving the Doctor from the Great Intelligence. (TV: The Rings of Akhaten, Hide, Clara and the TARDIS, The Name of the Doctor) Previously only the Doctor had been able to do this. (TV: Forest of the Dead, The Eleventh Hour, Day of the Moon)
 * The Eleventh Doctor continues to wear Amy Pond's reading glasses. (TV: The Angels Take Manhattan, The Snowmen, The Rings of Akhaten)
 * The Eleventh Doctor continues preferring odd reading material; this time it's Advanced Quantum Mechanics. (TV: The Wedding of River Song
 * Kate asks Osgood to tell "Malcolm" to change the batteries in the robotic ravens outside the Tower of London, and later calls Malcolm to request some of her father's files. This could be a reference to Malcolm Taylor, a UNIT scientist the Tenth Doctor met during his time on San Helios with the Swarm. (TV: Planet of the Dead) This also refers back to an earlier comment Kate made about having "ravens of death" to Amy Pond. (TV The Power of Three)
 * The Doctor again uses the phone on the outside of the TARDIS (TV: The Bells of Saint John) It had previously not been a real phone. (TV: The Empty Child) He later told Handles to remind him to rewire it back through the console. (TV: The Time of the Doctor)
 * Romana said previously that, on Gallifrey, paintings are done by computers. (TV: City of Death)
 * The Time Lords in the War Room mention that the High Council are holding an emergency session, and that they have plans of their own. (TV: The End of Time)
 * The War Doctor's statement "No more" in relation to the Time War was also said by Dalek Caan after he saw the Daleks through all of Time and Space. (TV: Journey's End)
 * Upon viewing the Moment's controls, the War Doctor asks "Why is there never a big red button?", which the Moment later modifies itself to incorporate. The Tenth Doctor previously mentioned he could never resist pressing a "great, big, threatening button." (TV: The Christmas Invasion)
 * Like the TARDIS, The Moment is confused by difference between the past and the future. (TV: The Doctor's Wife)
 * The Tenth Doctor's wedding with Elizabeth I is shown. (TV: The Shakespeare Code, The End of Time, The Beast Below, Amy's Choice, The Wedding of River Song) Presumably, the fact that he indicates no intention of returning to his new wife is what results in her antagonism towards him when they next met thirty years later in 1599. That encounter, however, happened earlier in his personal timeline, so he had no idea why she wanted his head. (TV: The Shakespeare Code)
 * A painting of the Tenth Doctor wearing Elizabethan clothing, including a large collar, is shown alongside a portrait of Elizabeth I's. Although Elizabeth I married the Tenth Doctor, she met both the Tenth and Eleventh Doctors. While investigating a time anomaly in Victorian London, there was a statue of the Eleventh Doctor in Elizabethan clothing. Eleven said he thought that Elizabeth I had made him wear the clothing, which he thought was for a private portrait. (GAME: The Eternity Clock)
 * The Tenth Doctor's reference to his wedding in The End of Time places his appearance here somewhere in the gap between The Waters of Mars and The End of Time, during which he traveled around for a bit to try to avoid his fate. He tells a rabbit he is 904 years old here, while in The End of Time he states he is 906. This suggests that, like the Eleventh Doctor's 200-year farewell tour but much shorter, the gap lasted several years.
 * The Fourth Doctor and UNIT previously fought the Zygons. (TV: Terror of the Zygons)
 * The Tenth Doctor previously encountered the Zygons in the Lake District in September 1909 in the company of Martha Jones. (PROSE: Sting of the Zygons) The Eleventh Doctor encountered them when he took Amy Pond and Rory Williams on an anniversary trip to the Savoy Hotel in 1890. (TV: The Power of Three)
 * While the Doctor is entranced by a fez, the painting that Clara stops to admire in the Under Gallery shows the latest variant of the Cybermen (TV: Nightmare in Silver)
 * The Tenth and Eleventh Doctors try "Reversing the polarity", a catchphrase his third incarnation used.
 * The War Doctor doesn't recognise his Tenth and Eleventh incarnations, believing them to be companions. The Fifth Doctor didn't recognise the Tenth, and believed him to be a fan. (TV: Time Crash)
 * The Eleventh Doctor once again displays his habit of giving other people nicknames based on their appearance; calling the Tenth Doctor "Matchstick Man" and later "Sandshoes", while calling the War Doctor "Granddad", just as he did with Amy Pond, Rory Williams and River Song in the White House. (TV: The Impossible Astronaut)
 * The War Doctor calls the Eleventh Doctor's bow-tie a "dicky bow", criticising the fashion choice as Amy Pond and Rory Williams had before. (TV: The Eleventh Hour, Amy's Choice, The Lodger)
 * When Clara exclaims that "there's three of them", Kate replies, "We have a precedent for that." (TV: The Three Doctors)
 * When the twelve Doctors contact the War Council to confirm they're ready to put Gallifrey into a pocket universe, the General complains "I didn't know when I was well off! All twelve of them!". This echoes Brigadier Lethbridge-Stewart's "Three of them, eh? I didn't know when I was well off!" (TV: The Three Doctors).
 * Kate Stewart asks Malcolm for one of her father's files; she says it may be filed under the 70s or the 80s "depending on the dating protocol", a clear reference to the UNIT dating controversy.
 * When Kate realizes there are multiple Doctors, she asks for a file code-named Cromer, which is a reference to her father at first believing the anti-matter universe to be Cromer. (TV: The Three Doctors)
 * When surrounded by Queen Elizabeth I's soldiers, the War Doctor asks the Tenth Doctor and the Eleventh Doctor if they were going to "assemble a cabinet at them". The phrase "build a cabinet" was previously used by River Song in relation to the sonic screwdriver, and "build some shelves" was similarly used by Jack Harkness. (TV: The Doctor Dances, Day of the Moon) Ironically, the three Doctors later used their screwdrivers offensively to blast a Dalek back with a force field, destroying it.
 * The War Doctor gripes at his future incarnations for brandishing their sonic screwdrivers as if they were water pistols. The Tenth Doctor actually used a water pistol against the Pyroviles. (TV: The Fires of Pompeii)
 * The Eleventh Doctor calls to Clara through a wormhole, referring to her as the "Wicked Witch of the Well." Hila Tacorien was previously referred to by this name due to the wormhole in Caliburn House. (TV: Hide)
 * The Black Archive of UNIT appears. (TV: Enemy of the Bane, COMIC: Don't Step on the Grass)
 * The War Doctor and his successors were haunted over the 2.47 billion children of Gallifrey they killed by using the Moment. When the Eleventh Doctor took Amy Pond to Starship UK, he was moved by the sound of children crying. (TV: The Beast Below)
 * The Tenth Doctor asks the Eleventh where he's going, to which the Eleventh Doctor replies, "Spoilers." (TV: Silence in the Library / Forest of the Dead et al.)
 * Kate encounters an alien which duplicates her appearance and impersonates her. This had previously happened when a Dæmon statue had taken her shape. (HOMEVID: Dæmos Rising)
 * When a Zygon is killed disguised as another creature, it keeps the form of that creature. (HOMEVID: Zygon: When Being You Just Isn't Enough)
 * When the War Doctor enters the Tenth Doctor's TARDIS he says he really "let it go"; the Eleventh comments that this was his "grunge phase". The Eleventh Doctor then loads his own 'desktop', changing the TARDIS design. The Tenth declares he doesn't like it. The Second Doctor said the same when he saw the Third Doctor's TARDIS (TV: The Three Doctors) and the redesigned UNIT HQ (TV: The Five Doctors), as did the Eleventh Doctor when visited Craig Owens in his new home. (TV: Closing Time) The Fifth Doctor also disliked the Tenth Doctor "changing the desktop theme" when they accidentally ran their TARDISes into each other. (TV: Time Crash) The TARDIS told the Doctor that she archived past and future versions of the console room in The Doctor's Wife. While changing the theme the Console Room briefly features a hybrid of the Tenth Doctor's Console Room and the original TARDIS roundel design which is later seen to be the War Doctor's TARDIS theme.
 * The episode continues the theme begun in the classic series of the Doctor's various selves having difficulty getting on with each other when they meet. (TV: The Three Doctors, The Five Doctors, The Two Doctors, Time Crash)
 * A pair of red heels identical to the ones River wore on the Byzantium are seen in the Black Archive. (TV: The Time of Angels)
 * Amy's pinwheel and Torchwood magnetic clamps are also seen in the Black Archive. (TV: Doomsday, The Eleventh Hour, et al.)
 * The Tenth Doctor, when returning to his own timeline, tells the Eleventh Doctor that he is glad his "future is in safe hands." These are the exact same words the First Doctor says to the Fifth Doctor upon the former's departure. (TV: The Five Doctors)
 * The security protocol for the Black Archive involves a self-destruct triggered through nuclear warhead detonation at the sacrifice of all human life in the blast radius. A similar nuclear option against alien attack was developed by UNIT in the form of the Osterhagen Project and was also nearly activated. (TV: The Stolen Earth, Journey's End)
 * When the Doctor calls from the TARDIS phone, his telephone number once again is 07700900461, as it was in (TV: The Stolen Earth).
 * This episode greatly resembles the events of The Fires of Pompeii; primarily, the sequence depicting the three Doctors placing their hands on the Moment resembles the scene in where Donna and the Doctor blow up Mount Vesuvius. In both cases, the Doctor was agonizing over a terrible decision (Pompeii or the world; Gallifrey or the universe), but somebody came to support him, and share the responsibility of pressing the button. These two stories also resemble each other in that the Doctor's companion convinces the Doctor to take a different path rather than resigning himself to an unalterable consequence. (Donna convinced him to save Caecilius and his family; Clara convinces the Doctor to save Gallifrey without destroying the Time Lords).
 * The Eleventh Doctor refers to his fate on Trenzalore. (TV: The Wedding of River Song, The Name of the Doctor, TV: The Time of the Doctor)
 * The Tenth Doctor, upon hearing of Trenzalore, says they need to take a different direction as "I don't want to go." His successor notes that "He always says that", as it was his last words before his regeneration. (TV: The End of Time)
 * Prior to regenerating, the War Doctor comments that his body is "wearing a bit thin", repeating the line spoken by the First Doctor immediately prior to his own regeneration into the Second Doctor. (TV: The Tenth Planet). He then hopes that "the ears are a bit less conspicuous this time"; the Ninth Doctor makes a reference to the size of his ears when meeting Rose. (TV:Rose)
 * For the War Doctor, the Tenth Doctor and the Eleventh Doctor, the events of this episode take place shortly before they regenerate. The War Doctor is seen regenerating at the end of the episode. Chronological evidence indicates the Tenth Doctor experiences this adventure during the period when he was on a "farewell tour", two years before his final adventure as depicted in The End of Time. Similarly, the Eleventh Doctor would regenerate in his next televised adventure, The Time of the Doctor. Interestingly enough, all three Doctors are living under the shadow of a prediction or expectation of their own death.
 * Conversely, the episode foreshadows the birth of the Twelfth Doctor, who arrives before his actual debut from the not-so-distant future to join his younger selves in transporting Gallifrey into another universe.
 * An eccentric, Doctor-like character who went by the name "the Curator" appeared in the story Summer Falls, which was marketed as being written by Amelia Williams.
 * While making the treaty, one of the Kate Stewarts can be heard saying "Look what happened to the Sycorax." (TV: The Christmas Invasion)
 * The Tenth Doctor tells the Eleventh Doctor "Oh, don't start" when he says "hello" to the Queen Elizabeths, recognising it as the same trick Captain Jack Harkness often pulled- flirting with people from the moment he said "hello" - one he repeatedly stopped. (TV: Bad Wolf, Utopia)

Home release
The Day of the Doctor was released on region 2 DVD, and region B 3D Blu-ray on 2nd December, 2013. The Night of the Doctor was also included on both versions. A region 1 DVD and a region A Blu-ray 3D/Blu-ray/DVD combo pack was released on 10th December, 2013.