public void AddMinuteShouldByEqualsTrue() { //Output 04/03/2010 17:02 datetime = DateTime.Parse("04/03/2010 17:00"); string microsoft_result = datetime.AddMinutes(2).ToString("dd/MM/yyyy HH:mm"); string new_datetime = my_datetime.AddMinutes("04/03/2010 17:00", 2); string my_result = my_datetime.Format(new_datetime, 1); Assert.AreEqual(microsoft_result, my_result); }