code: public int getShift(long utc) {
  
          if (utc <= 0) {
              return 0;
          }
  
          ExtendedLSE[] events = this.getEventsInDescendingOrder();
  
          for (int i = 0; i < events.length; i++) {
              ExtendedLSE lse = events[i];
  
              if (utc > lse.utc()) {
                  return 0;
              } else {
                  long start = lse.utc() - lse.getShift();
                  if (utc > start) { // Schaltbereich
                      return (int) (utc - start);
                  }
              }
          }
  
          return 0;
  
      }
docs: /*[deutsch]
  <p>Ermittelt die Verschiebung in Sekunden, wenn dieser Zeitpunkt
  &uuml;berhaupt eine Schaltsekunde repr&auml;sentiert. </p>
  
  @param   utc     elapsed SI-seconds relative to UTC epoch
  [1972-01-01T00:00:00Z] including leap seconds
  @return  {@code 1, 0, -1} if the argument denotes a positive leap second,
  no leap second or a negative leap second