public void NextYear_IfNextYearDoesNotHaveTheSameDayInTheSameMonthThenCalculateHowManyDaysIsMissingAndAddThatToTheLastDayInTheSameMonthNextYear()
 {
     var someBirthday = new DateTimeOffset(2008, 2, 29, 17, 0, 0, 0, TimeSpan.Zero);
     var nextYear = someBirthday.NextYear();
     Assert.AreEqual(new DateTimeOffset(2009, 3, 1, 17, 0, 0, 0, TimeSpan.Zero), nextYear);
 }
 public void NextYear_ReturnsTheSameDateButNextYear()
 {
     var birthday = new DateTimeOffset(1976, 12, 31, 17, 0, 0, 0, TimeSpan.Zero);
     var nextYear = birthday.NextYear();
     Assert.AreEqual(new DateTimeOffset(1977, 12, 31, 17, 0, 0, 0, TimeSpan.Zero), nextYear);
 }