Time zone of system already defined in client &1 (&2) and applied

What causes this issue?

The system time zhone must be maintained identically in all clients. It
has already been maintained in client &V1& in this system and copied (
&V2&).

System Response

The time zone is copied from client &V1& and is therefore no longer
ready for input.

How to fix this error?

If the time zones in the system are not correct, they must be
maintained in client &v1&.
The following alternative procedure is recommended for several clients
because of their interdependencies:
Deactivate time zones in all clients (transaction STZAC)
Maintain and activate system time zones in client 000
Activate time zones in all other clients

Error message extract from SAP system. Copyright SAP SE.