code: public boolean hasSameRules(TimeZone other) {
          return other != null &&
              getRawOffset() == other.getRawOffset() &&
              useDaylightTime() == other.useDaylightTime();
      }
docs: Returns true if this zone has the same rule and offset as another zone.
  That is, if this zone differs only in ID, if at all.  Returns false
  if the other zone is null.
  @param other the <code>TimeZone</code> object to be compared with
  @return true if the other zone is not null and is the same as this one,
  with the possible exception of the ID