Cognos Package DBMS

[sanchoniathon]

Hi,

Using a date function on a specific report (using Package A) in order to calculate the difference in hours between 2 timestamp fields and it works just fine.

Trying to use the same same function on another brand new report (using Package B) to get the difference between 2 timestamp fields but not working as for i now get the
following error message:
"RSV-VAL-0010 Failed to load the reportspecification. XQE-PLN-0098 The vendor specific fucntion "   " is not supported."

QUESTION : How can we calculate the difference between 2 timestamp fields in HOURS ?
QUESTION : how do we know what is the Data Base Management System being used by a specific cognos package ? I want to know ifi need to use MySQL, or SQL Server functions or what not.

Thanks.

p.s We do not have access to the Framework Manager application.