Game States

Game.State

public enum State
{
    Running,
    Destroying,
    Destroyed
}

if (Game.Current?.CurrentState == Game.State.Running) ...

Initial menu - no game state. As soon as loaded - Game.State.Running. Exit menu, other menus, time is not going - still "Running"

if (Game.Current?.GameStateManager.ActiveState.IsMenuState) ...

False when settlement menu is opened.

Active when some window is opened:

BannerBuilder
BannerEditor
Barber
CharacterDeveloper
Clan
Crafting
Education
GameOver
Inventory
Kingdom
Party
Quest
Tutorial

if (Game.Current?.GameStateManager.ActiveState.IsMission) ...

When Mission is active