diff --git a/src/linkgraph/linkgraphschedule.h b/src/linkgraph/linkgraphschedule.h
--- a/src/linkgraph/linkgraphschedule.h
+++ b/src/linkgraph/linkgraphschedule.h
@@ -58,7 +58,7 @@ public:
 	bool IsJoinWithUnfinishedJobDue() const;
 	void JoinNext();
 	void SpawnAll();
-	void ShiftDates(TimerGameCalendar::Date interval);
+	void ShiftDates(TimerGameEconomy::Date interval);
 
 	/**
 	 * Queue a link graph for execution.