You can use the date command to change the date and time on the system. Here's how you use the date command:-
YOU WILL NEED TO BE root,
f80>date mmddHHMM[ccyy]
Where mm = month in number
dd = day of the month
HH = hour
MM = minute
cc = century (this would be 20)
yy = year (eg. for 2002, it would be 02)
So to change the time to 14:20 on 23rd Oct. 2002 the command would be:-
f80>date 102314202002
Cheers,
Patrick