public void DifferenceInMintuesTest() { var ds1 = new DateSpan(2017, 1, 1, 11, 0, 0, 0); var ds2 = new DateSpan(2017, 1, 1, 12, 0, 0, 0); var difference = ds1.DifferenceInMinutes(ds2); Assert.AreEqual(-60d, difference); difference = ds2.DifferenceInMinutes(ds1); Assert.AreEqual(60d, difference); difference = ds1.DifferenceInMinutes(ds1); Assert.AreEqual(0d, difference); }