timer to stop a game and control time passed to play video games

[SirJean2134]

I want the Steam's team develop a timer to stop a game after a moment of time. By example, I plan to play 1 hour. After 55 minutes, I receive a notice about the end time. When it is done 1 hour, the game will close automatically and save the game. This way, it is possible to prevent or control the time passed to play video game for kids...and eventually me.

Thank you!

[hoot hoot]

I'm not certain since I've not set up my Steam for family use, but at least according to this page, you already can do this: Here [kidslox.com]