tour_monthly_pulse_effect

tour_monthly_pulse_effect = {
	scope:host = {
		save_scope_as = visiting_liege
	}
	scope:activity.var:stop_host = {
		save_scope_as = stop_host_scope
	}
	if = {
		limit = {
			scope:host = this
			NOT = {
				scope:activity = { exists = var:just_had_vassal_event }
			}
		}
		set_variable = {
			name = just_had_liege_event
			value = yes
			days = 3
		}
		trigger_event = {
			on_action = $ON_ACTION_POOL$_liege
		}
	}
	else_if = {
		limit = {
			scope:activity.var:stop_host = this
			NOT = {
				scope:activity = { exists = var:just_had_liege_event }
			}
		}
		set_variable = {
			name = just_had_vassal_event
			value = yes
			days = 3
		}
		trigger_event = {
			on_action = $ON_ACTION_POOL$_vassal
		}
	}
}

As written in game/common/scripted_effects/04_dlc_ep2_tour_effects.txt.