Sleeping is a vital thing is normal life. In Minecraft however, it's only handy for skipping the night.
If you want to make your survival experience a little more difficult, you might want to consider this vanilla mod.
What it basicly does:

- 1st night: Nothing happens
- 2nd night: You get slowness
- 3rd night: You get blindness as well
- 4th night: You get nausea as well
- 5th night: You get poison as well
- 6th night: You won't survive...

If you sleep or die, your sleep counter will be reset. If you die, your timer desynchronisises with the actual in-game time, this gets solved when you sleep.


You can click this link for the one command.

This mod does, sadly, not work on multiplayer servers.