After closing a session of the Stanley Parable, do not play for 10 years (120 months...3652 days...87648 hours...5258880 minutes). See you in a little while! Method 2:
Don't want to wait that long? Take 5 minutes instead. For people who want to know how to get this to actually work on Xbox consoles. Your console needs to be your home console to do this (tutorial)
- Play The Stanley Parable 'normally', online with automatic time settings.
- Quit the game.
- Go to Settings > General > Network Settings > Go Offline
- Restart your console (you can only change time when starting your Xbox console in an offline state)
- With your Xbox restarted disconnected from the internet, go to Settings > System > Time and change your console settings so they are a 10 years (and a day) in the future (I did 10 years and a day, just in case it technically didn't count the day of first playing the game).
- Start the Stanley Parable, and just play for a few minutes to ensure it triggers. I proceeded to the managers office following the narrator's instructions. It may work just launching in after the skippable intro, but I played a few minutes to be sure.
- Quit the game
- Go to Settings > General > Network Settings > Go Online
- Restart the Stanley Parable, load into your game, get your achievement.