public void AddWeekdays()
 {
     var date = new DateTimeOffset(2013, 7, 26, 0, 0, 0, DateTimeOffset.Now.Offset);
     Assert.AreEqual(new DateTimeOffset(2013, 7, 30, 0, 0, 0, DateTimeOffset.Now.Offset), date.AddWeekdays(2));
     Assert.AreEqual(new DateTimeOffset(2013, 7, 24, 0, 0, 0, DateTimeOffset.Now.Offset), date.AddWeekdays(-2));
 }