public void QuarterTest() { Parallel.ForEach(CultureTestData.Default, culture => { var calendar = culture.Calendar; foreach (QuarterKind yearQuarter in Enum.GetValues(typeof(QuarterKind))) { var months = TimeTool.GetMonthsOfQuarter(yearQuarter); var duration = TimeSpan.Zero; foreach (var month in months) { int monthDays = calendar.GetDaysInMonth(currentYear, month); duration += TimeSpan.FromDays(monthDays); } DurationUtil.Quarter(currentYear, yearQuarter).Should().Be(duration); DurationUtil.Quarter(currentYear, yearQuarter, calendar).Should().Be(duration); } }); }