Hi,
we recently installed DCNM 10 and also had the same problem. The way we changed the timezine and time is this:
From the server:
cd /usr/share/zoneinfo
ls
(find the timezone you need)
cd Europe
ls --> country (city)
cp /usr/share/zoneinfo/Europe/city /etc/localtime
and to change the time: date MMDDhhmmYYYY
MM: two digit month number
DD: two digit date
hh: two digit hour
mm: two digit minute
YYYY: four digit of year
Then we rebooted the system and checked date. Everything was ok.
Hope this helps.