Hi, I have just switched from log4j to logback. I would like to generate log containing results output by my program, and I want the file name to be SomePrefix.<timestamp>.someExt. I can do this programmatically but I'd like, if possible, to have all my logging configuration in my logback.xml file. Here's the appender I declared : <appender name="resultFile" class="ch.qos.logback.core.FileAppender"> <file>${logFolder}/SomePrefix.%d.someExt</file> <append>false</append> <filter class="ch.qos.logback.classic.filter.ThresholdFilter"> <level>info</level> </filter> <layout class="ch.qos.logback.classic.PatternLayout"> <pattern>%m%n</pattern> </layout> </appender> However the %d pattern is not interpreted, is there a way to do this? Maybe using a RollingFileAppender, but I don't see how. Regards, Nicolas Avant d'imprimer, pensez � l'environnement. Consider the environment before printing this mail.