After having set timeconfig to EST, I find that upon bootup, it sets itself for one day previous to the actual date. While I can fix this manually every time I need to reboot (not often), it's a bit of a pain.
Are your sure your hardware clock has the right date? To check the date on hardware clock, use /sbin/hwclock (/sbin/hwclock -u if you have chosen "Hardware clock set to GMT"). To set the hardware clock from the OS clock, use /sbin/hwclock -w (sbin/hwclock -wu if you have chosen "Hardware clock set to GMT"). Read hwclock manual page and/or Clock Mini-HOWTO for mor information