RollingFileAppender can roll log files based on size or date or both depending on the setting of the RollingStyle property. When set to Size the log file will be rolled once its size exceeds the MaximumFileSize. When set to Date the log file will be rolled once the date boundary specified in the DatePattern property is crossed. I have some troubles while writing logs from log4net to the file. I seem to do all as described in manual, but that does not work. Here is my logging.config file.