I have defined TimeBasedRollingPolicy using:

        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <!-- rollover every 12 hrs -->
            <fileNamePattern>${log.dir}/app.log.%d{yyyy-MM-dd-a}</fileNamePattern>
        </rollingPolicy>

But the log file is being rotated only once a day at 12 AM.

Looking at the code PeriodicityType enum has an entry 'HALF_DAY' but is not present in the valid list.

Is this supported by logback?

Thanks,
Srinivas