Cache current ticks per calendar day

src/settings.cpp

@@ -1309,6 +1309,8 @@ static void ChangeMinutesPerYear(int32_t new_value)
 		}
 	}
 
+	UpdateEffectiveDayLengthFactor();
+
 	/* If the setting value is not the default, force the game to use wallclock timekeeping units.
 	 * This can only happen in the menu, since the pre_cb ensures this setting can only be changed there, or if we're already using wallclock units.
 	 */