67th century

The 67th century, according to the Thirteenth Doctor, was a lovely century — "a bit tricky in the middle, but it's alright in the end." When reminded about the complexity of the technology of this time, she regretted not having visited this century more often. The Thirteenth Doctor, Graham O'Brien, Ryan Sinclair and Yasmin Khan visited Seffilun 27 during an unknown year in the 67th century. They were incapacitated by a sonic mine, then rescued and treated aboard the hospital ship Tsuranga, which came under attack by a Pting. (TV: The Tsuranga Conundrum)
In 6676 the Galactic Union is active researching Dalek Conquests (Mutually Assured Survival).