code: public static Date getDateFromTransactionId(long txnId) {
          long time = txnId >> (COUNTER_BITS + INITIATORID_BITS);
          time += VOLT_EPOCH;
          return new Date(time);
      }
docs: Given a transaction id, return the time of its creation
  by examining the embedded timestamp.
  @param txnId The transaction id value to examine.
  @return The Date object representing the time this transaction
  id was created.