This is defined on p. 20 of the rulebook.
Section 5.4 Sundown.
Once the High Noon phase is over, the Sundown Phase immediately begins. Any traits or effects
that apply continuously during Sundown start.
Now check for victory conditions to see if anybody’s won. If you have more control points than
the highest influence amongst all other players, you win. If two or more players meet this victory
condition, the one with the most control points wins. If that’s also tied, the player with the most
influence wins. If that’s also tied, play another day and check again for victory.
Any effects that require a check or game state change during Sundown are then resolved.
All players may choose to discard one card from their play hand, with the Winner choosing first.
All players then discard down or refill their play hand to their maximum hand size (normally 5
Next unboot all cards, and then turn and phase effects end in the following order:
1. The active window for Sundown effects now ends (so abilities or requirements based on
Sundown can no longer be triggered).
2. Effects that apply “during Sundown” end.
3. Effects that apply until the end of the turn end.
Abilities now refresh, which means they can be used again and are ready for the next day.
Finally, the day ends, and a new day begins.