public void TestFirstDayOfMonth()
        {
            RecurrenceRuleDayOfMonth rule = "DWM(Mo1)";

            Assert.Equal(1, rule.Multiplier);
            Assert.Equal(TimeInterval.DayOfWeekPerMonth, rule.Frequency);
            Assert.Single(rule.WeekDays);

            Assert.Contains(new DayOfWeekSpecified(DayOfWeek.Monday, +1), rule.WeekDays);
        }
        public void Test2ndSundayLastMonday()
        {
            RecurrenceRuleDayOfMonth rule = "DWM(Su2+Mo-1)";

            Assert.Equal(1, rule.Multiplier);
            Assert.Equal(TimeInterval.DayOfWeekPerMonth, rule.Frequency);
            Assert.Equal(2, rule.WeekDays.Count);

            Assert.Contains(new DayOfWeekSpecified(DayOfWeek.Sunday, +2), rule.WeekDays);
            Assert.Contains(new DayOfWeekSpecified(DayOfWeek.Monday, -1), rule.WeekDays);
        }