I've done it for the games free for a week-end on Steam, when I want to continue playing but I don't want to pay for the game. Of course it only work for singl

I've done it for the games free for a week-end on Steam, when I want to continue playing but I don't want to pay for the game. Of course it only work for single-player games. But changing the date of the computer quickly makes browsing internet unusable, due to certificate check failing.