public void TestCountMonths() { var dt1 = new DateTime(DateTime.Today.Year, 1, 14); var dt2 = new DateTime(DateTime.Today.Year - 1, 12, 18); var testResult = Rent.CountOfWholeCalendarMonthsBetween(dt1, dt2); Assert.AreEqual(0, testResult); testResult = Rent.CountOfWholeCalendarMonthsBetween(dt2, dt1); Assert.AreEqual(0, testResult); dt2 = new DateTime(DateTime.Today.Year - 1, 11, 5); testResult = Rent.CountOfWholeCalendarMonthsBetween(dt1, dt2); Assert.AreEqual(1, testResult); dt2 = new DateTime(DateTime.Today.Year, 1, 1); testResult = Rent.CountOfWholeCalendarMonthsBetween(dt1, dt2); Assert.AreEqual(0, testResult); dt1 = new DateTime(DateTime.Today.Year, 1, 1); dt2 = new DateTime(DateTime.Today.Year + 1, 1, 1); testResult = Rent.CountOfWholeCalendarMonthsBetween(dt1, dt2); Assert.AreEqual(12, testResult); dt1 = new DateTime(DateTime.Today.Year, 5, 5); dt2 = new DateTime(DateTime.Today.Year, 11, 1); testResult = Rent.CountOfWholeCalendarMonthsBetween(dt1, dt2); Assert.AreEqual(5, testResult); }