diff --git a/src/statusbar_gui.cpp b/src/statusbar_gui.cpp
--- a/src/statusbar_gui.cpp
+++ b/src/statusbar_gui.cpp
@@ -89,7 +89,7 @@ struct StatusBarWindow : Window {
 		Dimension d;
 		switch (widget) {
 			case WID_S_LEFT:
-				SetDParamMaxValue(0, DateAtStartOfYear(MAX_YEAR));
+				SetDParamMaxValue(0, TimerGameCalendar::DateAtStartOfYear(CalendarTime::MAX_YEAR));
 				d = GetStringBoundingBox(STR_JUST_DATE_LONG);
 				break;