diff --git a/src/newgrf.cpp b/src/newgrf.cpp
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -37,7 +37,6 @@
 #include "rev.h"
 #include "fios.h"
 #include "strings_func.h"
-#include "date_func.h"
 #include "timer/timer_game_tick.h"
 #include "timer/timer_game_calendar.h"
 #include "string_func.h"
@@ -6513,10 +6512,10 @@ bool GetGlobalVariable(byte param, uint3
 			return true;
 
 		case 0x02: { // detailed date information: month of year (bit 0-7), day of month (bit 8-12), leap year (bit 15), day of year (bit 16-24)
-			YearMonthDay ymd;
-			ConvertDateToYMD(TimerGameCalendar::date, &ymd);
-			TimerGameCalendar::Date start_of_year = ConvertYMDToDate(ymd.year, 0, 1);
-			*value = ymd.month | (ymd.day - 1) << 8 | (IsLeapYear(ymd.year) ? 1 << 15 : 0) | (TimerGameCalendar::date - start_of_year) << 16;
+			TimerGameCalendar::YearMonthDay ymd;
+			TimerGameCalendar::ConvertDateToYMD(TimerGameCalendar::date, &ymd);
+			TimerGameCalendar::Date start_of_year = TimerGameCalendar::ConvertYMDToDate(ymd.year, 0, 1);
+			*value = ymd.month | (ymd.day - 1) << 8 | (TimerGameCalendar::IsLeapYear(ymd.year) ? 1 << 15 : 0) | (TimerGameCalendar::date - start_of_year) << 16;
 			return true;
 		}
 
@@ -9947,7 +9946,7 @@ void LoadNewGRF(uint load_index, uint nu
 
 	if (_networking) {
 		TimerGameCalendar::year = _settings_game.game_creation.starting_year;
-		TimerGameCalendar::date = ConvertYMDToDate(TimerGameCalendar::year, 0, 1);
+		TimerGameCalendar::date = TimerGameCalendar::ConvertYMDToDate(TimerGameCalendar::year, 0, 1);
 		TimerGameCalendar::date_fract = 0;
 		TimerGameTick::counter = 0;
 		_display_opt  = 0;