message: Update/correct DateTime exception documentation
diff: @@ -96,7 +96,7 @@ namespace Azure { namespace Core {
  * @param fractionFormat The format for the fraction part of the Datetime. Only supported by
  * RFC 3339.
  *
  - * @throw std::length_error If year exceeds 9999, or if \p format is not recognized.
  + * @throw std::invalid_argument If year exceeds 9999, or if \p format is not recognized.
  */
  std::string GetString(DateFormat format, TimeFractionFormat fractionFormat) const;
  @@ -106,7 +106,7 @@ namespace Azure { namespace Core {
  *
  * @param format The representation format to use.
  *
  - * @throw std::length_error If year exceeds 9999, or if \p format is not recognized.
  + * @throw std::invalid_argument If year exceeds 9999, or if \p format is not recognized.
  */
  std::string GetString(DateFormat format) const
  {
  @@ -118,8 +118,7 @@ namespace Azure { namespace Core {
  *
  * @param fractionFormat The format that is applied to the fraction part from the RFC 3339 date.
  *
  - * @throw std::length_error If year exceeds 9999.
  - * @throw std::invalid_argument If \p format is not recognized.
  + * @throw std::invalid_argument If year exceeds 9999, or if \p format is not recognized.
  */
  std::string GetRfc3339String(TimeFractionFormat fractionFormat) const
  {
  