How to get the Stanley Parable Commitment Achievement

Another option:

In order to get this achievement you just need to:

1. Set your computer time to 11:58pm on a Monday.
2. Launch the game.
3. I'm not sure about starting to play, but I did.
4. Then you should set your computer to go into hibernation mode.
5. Turn off and then turn on the computer.
6. But don't boot into the system, go into the BIOS.
7. Change the system time to about 11:57pm on Tuesday.
8. Save, exit and boot into the system.
9. Play a game a bit and enjoy getting an achievement!

FYI, you can see I have gotten this achievement here.

I've tried this myself, and when they say you have to play the game for the entire duration of a Tuesday, they mean the entire duration, as in a full 24-hour period.

The most reliable way to do this would be to try keeping the game open from 11:59 PM on Monday, to 12:01 AM on Wednesday (times are based on your own system and not on the time at Valve). Also, you should turn off any sleep function on your computer that would shut down the game.