sets/gets a logical value which determines how dates are processed while building calendar - used for debugging
UK2GTFS_option_treatDatesAsInt(value)In the critical part of timetable building, handling dates as dates is about half the speed of handling as int so we treat them as integers. However that's a complete pain for debugging, so make it configurable. if errors are encountered during the timetable build phase, try setting this value to FALSE