Returns a field to access the day of week based on this {@code WeekFields}.
This is similar to {@link ChronoField#DAY_OF_WEEK} but uses values forthe day-of-week based on this {@code WeekFields}. The days are numbered from 1 to 7 where the {@link #getFirstDayOfWeek() first day-of-week} is assigned the value 1.
For example, if the first day-of-week is Sunday, then that will have the value 1, with other days ranging from Monday as 2 to Saturday as 7.
In the resolving phase of parsing, a localized day-of-week will be converted to a standardized {@code ChronoField} day-of-week.The day-of-week must be in the valid range 1 to 7. Other fields in this class build dates using the standardized day-of-week.
@return a field providing access to the day-of-week with localized numbering, not null