diff --git a/src/fios_gui.cpp b/src/fios_gui.cpp
--- a/src/fios_gui.cpp
+++ b/src/fios_gui.cpp
@@ -23,7 +23,7 @@
 #include "querystring_gui.h"
 #include "engine_func.h"
 #include "landscape_type.h"
-#include "date_func.h"
+#include "timer/timer_game_calendar.h"
 #include "core/geometry_func.hpp"
 #include "gamelog.h"
 #include "stringfilter_type.h"
@@ -520,7 +520,7 @@ public:
 
 			/* Start date (if available) */
 			if (_load_check_data.settings.game_creation.starting_year != 0) {
-				SetDParam(0, ConvertYMDToDate(_load_check_data.settings.game_creation.starting_year, 0, 1));
+				SetDParam(0, TimerGameCalendar::ConvertYMDToDate(_load_check_data.settings.game_creation.starting_year, 0, 1));
 				DrawString(tr, STR_NETWORK_SERVER_LIST_START_DATE);
 				tr.top += FONT_HEIGHT_NORMAL;
 			}