When running IFS Cloud a language is set for the user's database session. This is managed by the Fnd_Session_API package using the language the user specifies from the client at logon time. Once logged on the user cannot change the session language without logging off.
Changing the session language using API methods should not be attempted. Any such language changes will impact on the general translation of texts and date formatting.
All translated texts from the server are in the previously set language. This will include for example error and information messages, enumeration values etc.
Dates that are converted to a string representation in the server, as an example these would be shown in information messages created in the server, and are based on the Date Format specified for the used language. Please refer to Date Formatting for more details.