'net time server

Hi, Everyone 
           can anyone tell me how to set my system to update its time from an 
internet time server whenever i connect, 'cause at the moment whenever i 
reboot the 
my machine sets itself to some obscure time for example right now it says
sat. 4th may 2002 =) 
which is causing problems upgrading packages due to the fact that emerge 
thinks the new upgrade is older than the original package

my rc.conf is set to local and everything else seems ok so i figure an 
internet time server the best way to tackle this

thanks for any help
Regards James