ntp

To synchronize the time on a Ubuntu computer, with the time from a NTP server, you can simply run the following command:

sudo ntpdate 0.pool.ntp.org

Replace “0.pool.ntp.org” with your NTP time server of choice.
Example output:

$ sudo ntpdate 0.pool.ntp.org
 1 Jul 00:50:12 ntpdate[31843]: adjust time server 12.34.56.78 offset -0.001309 sec
$

Your time will now be synchronized to the time from the NTP server.
You can put this in a cron job to periodically update the time, to ensure its always up to date. This can be important when looking over logs. The right time makes things a lot easier.
If you need to change your timezone, please check out:
Change the Timezone in Ubuntu