code: public long getHeaderFieldDate(String name, long Default) {
          String value = getHeaderField(name);
          try {
              return Date.parse(value);
          } catch (Exception e) { }
          return Default;
      }
docs: Returns the value of the named field parsed as date.
  The result is the number of milliseconds since January 1, 1970 GMT
  represented by the named field.
  <p>
  This form of <code>getHeaderField</code> exists because some
  connection types (e.g., <code>http-ng</code>) have pre-parsed
  headers. Classes for that connection type can override this method
  and short-circuit the parsing.
  
  @param   name     the name of the header field.
  @param   Default   a default value.
  @return  the value of the field, parsed as a date. The value of the
  <code>Default</code> argument is returned if the field is
  missing or malformed.