Board Thread:The Reference Desk/@comment-60605-20140919101627/@comment-1259395-20141029223229

The Doctor mentions something about planting an acorn in the 1700s and it growing into a tree in 2016. It doesn't necessarily mean that the episode was set in 2016. I think the episode was set in 2017 at the earliest due to Strax recording Clara as being 27 in Deep Breath and she was born in 1989. Because she was picked up on Christmas day it is most likely that it was Christmas 2016 and then the rest of the episodes are set after New Year.