Don't be scared about the specific date of this achievement. IT CAN BE OBTAINED EVEN TODAY! But it will be tricky. What you need to do is:
1) Close your game.
2) Make sure your Steam isn't running! (IMPORTANT)
3) Change the date to 15/02/2015
4) Run Steam, it can be fussy but click "try again" until it opens. Don't be scared that some of the features don't load like the activity feed
5) Run Rome
6) Do what you have to do in order to obtain the achievment
7) Clck next round (it unlocked for me when I did that)
8) Close the game and set your date to correct one
9) PROFIT!!!