Change Oracle 19c PDB DBTIMEZONE

There is two node Oracle RAC 19.10 over RHEL 7.8. The DBTIMEZONE of the CDB is '+00:00' with SYSTIMESTAMP '+00:00'. One of the PDBs is with DBTIMEZONE '+03:00' with SYSTIMESTAMP '+00:00'. We would like to level out both DBTIMEZONEs as we change the DBTIMEZONE of the PDB to '+00:00'. The applications connect to the PDB via DB services. We would prefer to restart the DB instance by instance after relocating the services to the working instance so as not to interrupt the working process. Is this possible or is this hiding any risk for the DB and the whole system?