diff --git a/graph_gui.c b/graph_gui.c
--- a/graph_gui.c
+++ b/graph_gui.c
@@ -14,6 +14,7 @@
 #include "strings.h"
 #include "debug.h"
 #include "variables.h"
+#include "date.h"
 
 static uint _legend_excludebits;
 static uint _legend_cargobits;