World regions and their time zone names comply with the IANA specification for world regions and associated time zone names.

For more information about the IANA specifications, see http://www.iana.org/time-zones.

You need to set the II_TIMEZONE_NAME on the Ingres 11.1.0 instance to the equivalent Ingres Time Zone name for your region. The mappings of the IANA timezone to Ingres timezone are located here:

https://docs.actian.com/ingres/11.0/index.html#page/Ing_Install%2FTime_Zone_Name_Mappings.htm%23

However, if you are using an 11.x client against an older Ingres server, the client time zone names needs to match the previous time zone names to avoid time mismatches.