What I want to do is to make the age of people matter, to the extent that they are born very young, get married at some age, have kids, then get too old for that, maybe get a bit senile, then die of old age. Right now this is largely left up to the imaginations of the users, which is both good and bad I suppose.
Once I have this in place I need to relate a bit more to how old these people get and the general time-scale of the galaxy (and this may be a good opportunity to add races to the game).
But it's a conflict between having epic lasting empires, and some semblance of immersion to the people living in it. I don't mind Emperors who are 80,000 years old in the future, but I can see why people are bothered by it.
In modding, you can actually change the "time noun" so that it says anything, note that Earth map is supposed to have years, if you check the top right text :) So it's supported in-game. But there's no consistent canonical thought behind this yet.