Board Thread:The Panopticon/@comment-1783865-20181019214838

The date and year in The Ghost Monument isn't explicitly stated, but is there any way by what is given in the episode that we can deduce when the episode takes place?

We know that Desolation is left in uninhabitably horrible state. Ilin mentions the ancient settlers on the planet had named the TARDIS "The Ghost Monument", and given that we know it reappeared every thousand solar rotation added to the pace at which the suns move around the planet, we can say that this must have happened at least a couple of times. We also know that the TARDIS could have travelled in time after disappearing in Twice Upon a Time, but is not a certainty. We also know that Desolation was in its natural orbit when the TARDIS landed and we can also add how far it has fallen out since then.

What we don't know for sure is whether the Doctor's transportation machine in The Woman Who Fell to Earth, which is partially human tech and partially Stenza tech and is set to track artron energy, also allows for travelling in time. 