C# (CSharp) Weekday.ToIndex примеры использования

Пример #1

        public static Weekday Add(this Weekday day, int value)
        {
            int a = (day.ToIndex() + value) % 7;

            if (a < 0)
            {
                a = 7 + a;
            }
            return(FromIndex(a));
        }