I have identified a bug in Openfire 3.9.3 regarding log rotation by date (it is being done at 11h59 AM instead of 23h59) in the class :
I created a discussion on the Support forum and provided a solution. Although it is a small fix, it has a big impact on audit activities.
Please take a look at this issue and consider integrating the fix in future releases.
Issue and solution can be found here
Openfire 3.9.3 and log rotation issue (based on date)
Thanks and regards,