Re: System/Bios Time
It looks like your bios (hardware) clock was set to local time but
you told the debian installer that it was set to UTC (or maybe vice
versa) then for some reason the bios clock drifted about a half-hour
off (not sure what would cause that).
Rather than ntpdate, I'd use ntp. Ntpdate runs just once at system
startup. Ntp runs as a daemon and keeps the clock in sync with the
reference servers continuously.
More importantly, from your point of view, if your hardware clock is
drifting (as it appears to be), ntp will make an attempt to correct
it every once in a while -- particularly at system shutdown time.
Ntpdate does not do that.