When does Doctor Who: The Church on Ruby Road return?

Doctor Who is a British science fiction television series broadcast by the BBC since 1963. The series depicts the adventures of an extraterrestrial being called the Doctor, part of a humanoid species called Time Lords. The Doctor travels in the universe and in time using a time travelling spaceship called the TARDIS, which externally appears as a British police box. The transition from one actor to another is written into the plot of the series with the concept of regeneration into a new incarnation, a plot device in which, when a Time Lord is fatally injured, their cells regenerate and they are reincarnated.
The Doctor is a rogue Time Lord with somewhat unknown origins who goes by the name "the Doctor" The Doctor fled Gallifrey, the planet of the Time Lords, in a stolen TARDIS ("Time and Relative Dimension(s) in Space"), a time machine that travels by materialising into, and dematerialising out of, the time vortex. The TARDIS has a vast interior but appears smaller on the outside, and is equipped with a "chameleon circuit"