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