This is what happens when you start grabbing FreeBSD code!!
(Well server code and port to clients)

Apple had the forethought to run newsyslog under launchd to combat this problem, but didn't check to see that newsyslog will only rotate logs if you are within 1 hour of midnight!

It's worth noting that there is an interesting debate on the apple discussions forum, but it would seem newsyslog may even be run every hour, but again, rotation only occurs around midnight.

in the man page for newsyslog, it appears to imply that it is run every hour, but if you read it carefully it says that it *could* be run every hour because it is very light on resources.

that might be the source of the confusion