The Time Lord Academy/Policy on dating Stories?

So I'm relatively new here so I'm wondering what the policy on dating articles is here on the Wiki. I'll use the stories The Sands of Life and War Against the Laan as examples.

So in these stories there is no specific date given, however it is mentioned that the position of President of Earth was first created 75 years ago. Meanwhile, from An Earthly Child we know that the president of Earth was made a regular role at some point between the end of the Dalek Invasion of Earth (2167) and 2190. Is this sufficient information to date the story as the 23 Century?

Thanks for any advice.

P.S. in an Earthly Child its the President of the Earth Council, but I think we can assume this to be the same as the President of Earth, just like we assume the title the President of the High Council of Gallifrey to be the President of Gallifrey.