Add method for whether calendar is frozen

src/date.cpp

@@ -275,6 +275,12 @@ EconTime::Date EconTime::ConvertYMDToDate(EconTime::Year year, EconTime::Month m
 	return CalTime::ConvertYMDToDate(year.base(), month, day).base();
 }
 
+bool CalTime::IsCalendarFrozen(bool newgame)
+{
+	GameSettings &settings = (newgame) ? _settings_newgame : _settings_game;
+	return settings.economy.timekeeping_units == TKU_WALLCLOCK && settings.economy.minutes_per_calendar_year == CalTime::FROZEN_MINUTES_PER_YEAR;
+}
+
 bool EconTime::UsingWallclockUnits(bool newgame)
 {
 	if (newgame) return (_settings_newgame.economy.timekeeping_units == TKU_WALLCLOCK);
@@ -417,10 +423,10 @@ static void OnNewEconomyDay()
 static void IncreaseCalendarDate()
 {
 	/* If calendar day progress is frozen, don't try to advance time. */
-	if (_settings_game.economy.minutes_per_calendar_year == CalTime::FROZEN_MINUTES_PER_YEAR) return;
+	if (CalTime::IsCalendarFrozen()) return;
 
 	/* If we are using a non-default calendar progression speed, we need to check the sub_date_fract before updating date_fract. */
-	if (_settings_game.economy.minutes_per_calendar_year != CalTime::DEF_MINUTES_PER_YEAR) {
+	if (_settings_game.economy.timekeeping_units == TKU_WALLCLOCK && _settings_game.economy.minutes_per_calendar_year != CalTime::DEF_MINUTES_PER_YEAR) {
 		CalTime::Detail::now.sub_date_fract++;
 
 		/* Check if we are ready to increment date_fract */

src/date_type.h

@@ -195,6 +195,8 @@ struct CalTime : public DateDetail::BaseTime<struct CalendarTimeTag> {
 		return ConvertYMDToDate(ymd.year, ymd.month, ymd.day);
 	}
 
+	static bool IsCalendarFrozen(bool newgame = false);
+
 	/**
 	 * Calculate the year of a given date.
 	 * @param date The date to consider.

src/vehicle.cpp

@@ -1565,7 +1565,7 @@ void CallVehicleTicks()
 
 	if (TickSkipCounter() == 0) RunVehicleDayProc();
 
-	if (EconTime::UsingWallclockUnits() && _settings_game.economy.minutes_per_calendar_year != CalTime::FROZEN_MINUTES_PER_YEAR && CalTime::Detail::now.sub_date_fract == 0) {
+	if (EconTime::UsingWallclockUnits() && !CalTime::IsCalendarFrozen() && CalTime::Detail::now.sub_date_fract == 0) {
 		RunVehicleCalendarDayProc();
 	}