Is there a Sleep Timer?

Bomiboll wrote:

Is there a stopwatch app that count-up as soon as I press a key or close the lid?

To the best of my knowledge, the stopwatch built into the Mac starts when you press the button. Whether or not you could build a shortcut that enables it when you close the lid, I don't know. But the difference between pressing the button and closing the lid should only be a matter of 10 seconds or so.

The timer in the built-in Clock app appears to do that. Note that you will not hear any notification if the timer ends while the lid is closed.

Glad it helped.