I have a CCME 4.0 with 5 ip phones 7940, and 2 ip phones 7970.
The 5 phones 7940 have in the display the hour correct, but the 2 phones 7970 have one hour less that the others.
I did a set the clock time-zone
and I enable the cn files
I need a special temple maybe?
no create cnf-files and create cnf-files
This may also be related to the;
clock timezone command
Troubleshooting Incorrect Time Stamp on IP Phones in Cisco Unified CME
This was really covered nicely by Paul in this thread :)
Hope this helps!