The Day of the Doctor (in-universe episode)

The Day of the Doctor (WC: The Zygon Isolation) was an episode of Doctor Who (TV: The Doctor Appears, WC: The Zygon Isolation) released in 2013 in 3D. (TV: The Doctor Appears) By 10th of May, 2020, the episode was available on BBC iPlayer, and was Petronella Osgood's "Next Episode". (WC: The Zygon Isolation)

Important note
This is an in-universe counterpart of the real world Doctor Who television story The Day of the Doctor that exists within the Doctor's universe.

Information from invalid sources
Strax brought his entire clone batch to watch The Day of the Doctor with him, and also gave advice on cinema etiquette to other patrons. The Eleventh Doctor and the Tenth Doctor also hijacked the screen to alert the audience to the presence of Zygons and give safety precautions on their 3D glasses until they became distracted by the War Doctor. (NOTVALID: Cinema Introduction)

Strax later assembled mass audiences together in 2020 for a special rewatch of The Day of the Doctor, in "groundbreaking 2D". He remarks that all of the original Doctors returned, except most of them, and that actors such as John Hurt and Billie Piper's return, and Tom Baker starring as "who was that supposed to be anyway?" Strax leaned in close, claiming that this was the story that changed everything, unless it didn't, as he found it not to be very clear, though he could say with certainty that the Time Lords were back for good. (NOTVALID: Strax Saves the Day)