You can pass DATETIME and DATETIME-TZ fields as parameters between local and remote internal procedures, external procedures, user-defined functions, and methods. This parameter passing is supported across all supported interfaces. However, you should use DATETIME-TZ (rather than DATETIME) for application server and Web services parameters since the client machine and the server machine can be in different time zones. If you use DATETIME, you could potentially lose data.

User-defined functions and methods can have DATETIME and DATETIME-TZ return values.