code: public Date getTimestamp(byte[] data) {
      long secondsAndMicros = ByteBuffer.wrap(data).getLong(INITV_BASE + INITV_TIMESTAMP_OFFSET);
      return new Date(secsAndMicrosToMillis(secondsAndMicros));
    }
docs: Returns the {@code timestamp} field from encrypted or decrypted data. Assumes that its
  initialization vector has the structure {@code (timestamp, serverId)}.
  
  @param data Encrypted or decrypted data (the initialization vector is never encrypted)
  @return Timestamp subfield of the initialization vector, in the form of a Date.
  This assumes the init vector was created with {@link #createInitVector(Date, long)}
  or similar method consistent with the DoubleClick crypto specification