I'm not sure what you mean.
My public header contains the real life time and date.
"0010/18052010/U779/212/1OF1/SJN DGT"
Format:
"<hhmm>/<ddmmyyyy>/<SubID>/<MsgNum>OF<MaxMsgNum>/<Trigram>
Where <hhmm> and <ddmmyyyy> the real life time and date represent.