At this moment you cannot specify a template for the log file name (that relies on the current date).
This capability can be added in the following way:
introduce 'LogFileNameFormat' delegate in FileLoggerOptions
if this delegate is defined check for the new file name in FileLoggerProvider.CheckForNewLogFile method (right now it checks current log size if max limit is specified)
How to use your library to creating new *.log files every day