code: public final void setUtc(final boolean utc) {
          if (!Value.DATE.equals(type)) {
              for (Date date: this) {
                  ((DateTime) date).setUtc(utc);
              }
          }
          this.timeZone = null;
          this.utc = utc;
      }
docs: Sets whether this list is in UTC or local time format.
  
  @param utc
  The utc to set.