4 files changed, 13 insertions, 9 deletions
diff --git a/src/date.cpp b/src/date.cpp
index 908f94041..f6f4f19aa 100644
--- a/src/date.cpp
+++ b/src/date.cpp
@@ -77,11 +77,6 @@ static const uint16 _accum_days_for_month[] = {
 	ACCUM_SEP, ACCUM_OCT, ACCUM_NOV, ACCUM_DEC,
 };
 
-static inline bool IsLeapYear(Year yr)
-{
-	return yr % 4 == 0 && (yr % 100 != 0 || yr % 400 == 0);
-}
-
 /**
  * Converts a Date to a Year, Month & Day.
  * @param date the date to convert from
diff --git a/src/date_func.h b/src/date_func.h
index d196fdb52..8c484b2c4 100644
--- a/src/date_func.h
+++ b/src/date_func.h
@@ -16,4 +16,9 @@ void SetDate(Date date);
 void ConvertDateToYMD(Date date, YearMonthDay *ymd);
 Date ConvertYMDToDate(Year year, Month month, Day day);
 
+static inline bool IsLeapYear(Year yr)
+{
+	return yr % 4 == 0 && (yr % 100 != 0 || yr % 400 == 0);
+}
+
 #endif /* DATE_FUNC_H */
diff --git a/src/date_type.h b/src/date_type.h
index 86885faeb..ddb6dfc7c 100644
--- a/src/date_type.h
+++ b/src/date_type.h
@@ -46,8 +46,8 @@ typedef uint8  Day;
 
 struct YearMonthDay {
 	Year  year;
-	Month month;
-	Day   day;
+	Month month; ///< 0 - 11
+	Day   day;   ///< 1 - 31
 };
 
 static const Year INVALID_YEAR = -1;
diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index f1fe64635..3885fcf23 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -3566,9 +3566,13 @@ bool GetGlobalVariable(byte param, uint32 *value)
 			*value = Clamp(_cur_year, ORIGINAL_BASE_YEAR, ORIGINAL_MAX_YEAR) - ORIGINAL_BASE_YEAR;
 			return true;
 
-		case 0x02: // current month
-			*value = _cur_month;
+		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(_date, &ymd);
+			Date start_of_year = ConvertYMDToDate(ymd.year, 0, 1);
+			*value = ymd.month | (ymd.day - 1) << 8 | (IsLeapYear(ymd.year) ? 1 << 15 : 0) | (_date - start_of_year) << 16;
 			return true;
+		}
 
 		case 0x03: // current climate, 0=temp, 1=arctic, 2=trop, 3=toyland
 			*value = _settings_game.game_creation.landscape;