How to change time on a NEC Vanguard voice mail.

Do the following without lifting the handset or pressing any other keys first.
From extension 300, dial #TD (#83).
Enter the time in 24-hour clock using hours (2 digits), minutes (2 digits)
and seconds (2 digits).
Press HOLD.
Enter the date using month (2 digits), day (2 digits), and year (4 digits).
Press HOLD, then SPK to exit.