Following these instructions worked great for me:
http://derekmolloy.ie/automatically-setting-the-beaglebone-black-time-using-ntp/
you can simply set a cron every hour with ntpdate, or use ntpd, and of course you will need to chance the localtime file for your timezone
this tutorial is really helpful http://www.gigamegablog.com/2012/01/29/beaglebone-linux-101-configuring-angstrom-linux/
by the way the new release of may is doing it automatically 
nice good to know 