The first part updates your system time, the second part ( after the && ) updates the BIOS clock, so if you only want your system time updated leave the “&& hwclock --systohc” off.
For the real time fanatics we can even automate the process . . . ( well isn´t that what computers are for ? )
You can add the line above at the end of /etc/rc.d/rc.local to make it update every time you boot. Of course you need a broadband connection that is started during boot for it to be effective.
NOTE: You will need to have “rdate” installed ( check your package manager )
PS: If you get an odd time, rightclick the clock, select "Adjust Time and Date" and check if the timezone is set correctly
-- Jan 16 2004 ( Revised Dec 15 2005 ) --