See if this procedure helps...
Go into your ACS interface ->System Configuration ->logging. There you can edit the preference for each type of log file. Here, you will also have the choice of creating a new log file each day, week, month, or according to the size of the log file in bytes. But you will have to go through each section of logging and set this for each individual CSV file.
I am not sure if this is what you want. Are there any other ways to do this.
