You posted the question under Eikon Data APIs so I am assuming that you are using Eikon Data APIs.
Anyway, please clarify your question in more detail, what API product you are using on Java programming language?
What timezone you are referring to? Do you mean it is related to API product?
Are you asking a standard Java programming language question (not related to Refinitiv Product)?
Sorry for that, am not sure which group the question belongs to. In general, am just curious any Refinitiv Java API ( Not Python or C# or ...) which returns list of time zone format supported by Refinitiv EDP platform. So that I need to store different time zone format in DB from Java application.