> 2. Debian 8.6 w MATE run from LIVE DVD _displays_ the correct time
> 3. Debian 8.6 w MATE installed from DVD 1 of 13 with aid of custom
> preseed.cfg
> _displays_ a time 5 hours earlier.
My guess: the Live DVD uses NTP so as not to depend on the hwclock
whereas your installs don't.
Stefan