Change timezone of log entry

My application config looks like this:

logging.file.name=/var/log/bup/bapserver/services-server.log
logging.pattern.console=%d{ISO8601} [%-20.20t][%-5p][%-40.40c] - %m%n
logging.pattern.file=%d{ISO8601} [%-20.20t][%-5p][%-40.40c] - %m%n
logging.level.root=WARN
logging.level.com.mgmtp.a12.uaa.authorization.security=WARN

The log entries in the services-server.log.json look like

{"@timestamp":"2023-04-28T07:06:33.191Z", "log.level": "WARN", "message":"recalculation or ranks triggered, but it is disabled by configuration => No action performed.", "ecs.version": "1.2.0","service.name":"bup-ci-bapserver","event.dataset":"bup-ci-bapserver.log","process.thread.name":"quartzScheduler_Worker-1","log.logger":"com.mgmtp.a12.dataservices.model.relationship.persistence.internal.DefragmentRanksJob"}

How can I change the timestamp to be written in “German timezone” (with six or nine decimal places), meaning that ist looks like
2023-04-28T09:06:33.191000111+02:00
?

I have already played around with the logging.pattern.file parameter, but that doesn’t seem to have any effect.

After further insight, I found a logback-spring.xml, that included the elastic file appender which then wrote the logfile. That file appender doesn’t care for the logging.pattern.file entry. I then changed the file appender to spring’s default one and now it works.

See new logback-spring.xml here:

<configuration>

    <include resource="org/springframework/boot/logging/logback/defaults.xml"/>
    <include resource="org/springframework/boot/logging/logback/console-appender.xml" />
    <include resource="org/springframework/boot/logging/logback/file-appender.xml" />
    <!-- <include resource="co/elastic/logging/logback/boot/ecs-file-appender.xml" /> -->

    <root level="INFO">
        <appender-ref ref="CONSOLE"/>
        <appender-ref ref="FILE"/>
        <!-- <appender-ref ref="ECS_JSON_FILE"/> -->
    </root>

</configuration>