Countdown to Zero

Not sure what you mean. Are you talking about day change or end of map times up for all?

If you’re talking about the one on the top right next to the calendar, that’s just day change. Healing, revolts and morale changes without good take place on that time. If you’re talking about the one that pops up after dozens of days, then that’s the end timer. The game ends once it reaches 0 and the current placings (1st to last) become final ranks, with the first place person or coalition as winner.