code: public void setStartYear(int year) {
          if (isFrozen()) {
              throw new UnsupportedOperationException("Attempt to modify a frozen SimpleTimeZone instance.");
          }
  
          getSTZInfo().sy = year;
          this.startYear = year;
          transitionRulesInitialized = false;
      }
docs: Sets the daylight savings starting year.
  
  @param year  The daylight savings starting year.