Sets or gets a list of days in the week that are not selectable.
Setting the disabledDaysOfWeek property sets a list of days of the week that can't be selected in the appointment field's date element.
Weekdays are numbered 0 to 6 with Sunday = 0.
Setting disabledDaysOfWeek to [] clears the list and enables all days of the week.
Getting the disabledDaysOfWeek property returns the list of disabled days of the week set in the Editor or API.
Note: Setting disabledDaysOfWeek overrides any settings made in the Editor.