To adjusts system date and time.

Time zone information is stored in the configuration file /etc/timezone an can be checked using the cat command:

root@server:~# cat /etc/timezone
Europe/Lisbon

To adjust the system timezone, use the dpkg-reconfigure tzdata:

root@server:~# dpkg-reconfigure tzdata

Choose the geographical area:

Then the region or city where the system is physically located:

The current default time zone is now:

Current default time zone: 'Europe/Lisbon'
Local time is now:      Mon May  6 18:30:14 WEST 2013.
Universal Time is now:  Mon May  6 17:30:14 UTC 2013.

date can be used to show the actual system date and time:

root@server:~# date
Mon May  6 18:31:38 WEST 2013

date can also be used to quickly adjust system date and time. The syntax is “date MMDDhhmm”:

root@server:~# date 05061834
Mon May  6 18:34:00 WEST 2013