gistfile1.cs

// before

var bdayEl = el.Descendant("DatumNarozeni");
var birthday = bdayEl != null ? (DateTime?)Convert.ToDateTime(bdayEl.Value) : null;

// after Maybe

var birthday = from bday in el.Descendant("DatumNarozeni").ToMaybe()
               select Convert.ToDateTime(bday.Value).ToMaybe();