Days Till Next Birthday

public static int DaysTillNextBirthday(DateTime dateOfBirth) {

  //full days (whole, 24-hr periods) until next birthday...
  int result = 0;
  DateTime dtToday = DateTime.Now;
  DateTime dtNextBirthday = new DateTime(dtToday.Year, dateOfBirth.Month,
      dateOfBirth.Day);
  TimeSpan tsDifference = dtNextBirthday - dtToday;
  if (tsDifference.Days < 0)
  {
      //already had birthday this year
      tsDifference = dtNextBirthday.AddYears(1) - dtToday;
  }
  result = tsDifference.Days;
  return result;
}