It would be useful to have some macro for timezone (of the server, or maybe also the proxy).

It is often useful, especially in trans-regional or global projects/services, to have information about timezone e.g. in e-mail notifications. It may be configured statically in message body, but this is not practical for message template configurations portability (multiple server or proxy  instances in multiple timezones), and needs to be changed too when e.g. migrating betwen timezones.