public void EnrichData_Expected_FirstTimePeriodIsBeginingOfTheDay() { // Arrange var powerTrade = new Fixture().Create <PowerTrade>(); powerTrade.Date = powerTrade.Date.Date; // Act var result = DateTimeManager.EnrichDataWithDates(powerTrade); // Assert TimeSpan.TryParse(result.First().Period, out TimeSpan firstTimePeriod); var beginingOfDayUtc = DateTimeManager.CalculateBegginingOfReportingDayUtc(powerTrade.Date).TimeOfDay; Assert.AreEqual(firstTimePeriod, beginingOfDayUtc); }