The system date and time is set with the date command.
You must have root user authority to change the system date or time.
The date command allows the date or time to specified in one of several different formats. One form of the date command is:
date mmddHHMM.SSyy
where mm is the month, dd is the day of the month, HH is the hour, MM is the minutes, SS is the seconds, and yy is the last two digits of the year.