I want to give a shout-out to a fellow nerd named Kenny Ray.

When writing The Martian, I was as scientifically accurate as possible. I even worked out the orbital trajectories that they took to get to and from Mars. I had to write software to help me work out a constantly-accelerating orbital path. I also had to find a launch window such that Earth and Mars were properly positioned.

So I had to pick a real-world date for the launch of Ares 3. I never specifically tell the rea...der any dates, but I had a spreadsheet to tell me the actual date of each sol. And of course everything that was date-sensitive is accurate (like transmission times, etc.)