Unable to not set default value for Day Of Week field type (even if not required)

[nairdo]

Created a new group attribute called Meeting Day of Week with Field Type "Day Of Week". The Required checkbox is unchecked. When I try to set the Default Value to empty, and then save, the default value is set back to Sunday. Also when looking at groups, it appears they have an attribute value of Sunday when none was set.

[nairdo]

It looks like the DayOfWeekPicker currently always returns Sunday when nothing is selected:

        public DayOfWeek SelectedDayOfWeek
        {
            get
            {
                int? result = this.SelectedValueAsInt();
                if (result.HasValue)
                {
                    return (DayOfWeek)result.Value;
                }
                else
                {
                    return DayOfWeek.Sunday;
                }
            }