Bar Data Values
Numeric code for day of week of this bar
(there are no Saturday or Sunday bars in any known data series)
Negative offsets, e.g. DayOfWeek[-1], can be legitimately used to obtain the weekday of a future bar. This works even if the offset goes beyond the range of the currently loaded data file. For best results when future dates are required, a HolidayList should also be provided.