Spread life and death.
Henzell says...
  1. Dawdle too much and you permanently lose max hp. It's very unlikely to matter normally, but you can hit E to see it or enable your rcfile to always show it.
  2. The clock is per branch. When you enter a new branch, 60k aut (6k turns) are put on the clock. If the clock drops to 0, you permanently lose max HP and more time is added to the clock. When you enter a new floor on that branch, the clock gets another 60k aut, up to a max of 270k. Chei followers lose only 2 points of clock every 3 aut.
  3. The clock doesn't run in the Abyss. Pan works as normal. If you get the Orb or complete a {ziggurat}, the clock turns off permanently. Meteorans only get 6k aut (600 turns) per floor and when entering a new branch.
  4. Prior to 0.30, the Zot clock drained hp. The Zot clock replaced {hunger} in 0.26.

Information based on master branch and the great LearnDB.
© Dungeon Crawl Stone Soup, 2010.